Just a few general tips for the folks with itchy soldering irons... 
1) Get good equipment. A $7.99 radio shack soldering iron might get hot, but you are going to have a much easier time buying a GOOD soldering iron with a selectable heat control. Weller makes one for under $100 that you can buy online. This way you can solder pcb's without burning them... and if you need to rewire a guitar or amp, you can crank the heat up and solder on the back of the pots with no issues.
2) Get a decent desoldering tool. My personal favorite are the suction types - you heat up the solder joint, and it vacuums up the solder. Radio Shack makes a blue one that looks like a marital aid for under $10. This is so much neater than heating up solder joints and yanking on parts. If you desolder correctly, the parts can fall out of the pcb!
3) If you have a part you are going to have to pull on to get out, be careful using needlenose pliers. You can't tell how hot the board is getting, and if you're wrestling with it too long you're going to burn it. In most cases I try to use my FINGERS to pull on the part while I heat the solder - if it's too hot for my fingers then it's getting too hot for the PCB too. Nothing encourages quick part removal than burning sensations on your fingers.
4) Especially on older parts that you are installing, use some steel wool to clean the leads. I had some vintage carbon comp resistors I was using on a mod, and the leads had a little corrosion. A quick wipe with some steel wool and they were shiny, and ready for a good solder joint. I've also seen this to a lesser degree on new caps and resistors.
5) When at all possible, take the module apart. It makes for a cleaner mod. I started doing a few mods for lower $ from the top, but it just makes for a better/neater mod to do it from the underside like the factory. If you are nervous about taking the module apart, you probably don't have any business replacing parts on it either.
6) When you take the module apart, note how many washers are on the pot shafts. MAKE SURE you put just as many back - no more, no less.
7) Use the right tools for the job. Wrong size screwdrivers will cause all sorts of issues. Strip out a screw on a module and it's a real pain to fix. Trust me. It seems like the old black ones were really bad at this.
8) speaking of the black screws, almost all of them have that green goop on them. Sometimes it gets in the grooves on the screw where your screwdriver mates to it... if this happens, use an x-acto knife or something pointy to scrape it out. Otherwise you can't get a good hold on the screw and it will strip out.
9) Cut all your leads as short as possible. If they are too long and touch the metal carrier under the PCB, there's a good chance your module won't work.
10) make sure capacitors with a +/- designation are polarized properly. LEDs too. Resistors can go in either direction, same with most of your capacitors - orange drops, mica and ceramics can go either way. The ones that look like little barrels are usually polarized though.
11) measure twice, cut once.
1) Get good equipment. A $7.99 radio shack soldering iron might get hot, but you are going to have a much easier time buying a GOOD soldering iron with a selectable heat control. Weller makes one for under $100 that you can buy online. This way you can solder pcb's without burning them... and if you need to rewire a guitar or amp, you can crank the heat up and solder on the back of the pots with no issues.
2) Get a decent desoldering tool. My personal favorite are the suction types - you heat up the solder joint, and it vacuums up the solder. Radio Shack makes a blue one that looks like a marital aid for under $10. This is so much neater than heating up solder joints and yanking on parts. If you desolder correctly, the parts can fall out of the pcb!
3) If you have a part you are going to have to pull on to get out, be careful using needlenose pliers. You can't tell how hot the board is getting, and if you're wrestling with it too long you're going to burn it. In most cases I try to use my FINGERS to pull on the part while I heat the solder - if it's too hot for my fingers then it's getting too hot for the PCB too. Nothing encourages quick part removal than burning sensations on your fingers.
4) Especially on older parts that you are installing, use some steel wool to clean the leads. I had some vintage carbon comp resistors I was using on a mod, and the leads had a little corrosion. A quick wipe with some steel wool and they were shiny, and ready for a good solder joint. I've also seen this to a lesser degree on new caps and resistors.
5) When at all possible, take the module apart. It makes for a cleaner mod. I started doing a few mods for lower $ from the top, but it just makes for a better/neater mod to do it from the underside like the factory. If you are nervous about taking the module apart, you probably don't have any business replacing parts on it either.
6) When you take the module apart, note how many washers are on the pot shafts. MAKE SURE you put just as many back - no more, no less.
7) Use the right tools for the job. Wrong size screwdrivers will cause all sorts of issues. Strip out a screw on a module and it's a real pain to fix. Trust me.
It seems like the old black ones were really bad at this.8) speaking of the black screws, almost all of them have that green goop on them. Sometimes it gets in the grooves on the screw where your screwdriver mates to it... if this happens, use an x-acto knife or something pointy to scrape it out. Otherwise you can't get a good hold on the screw and it will strip out.
9) Cut all your leads as short as possible. If they are too long and touch the metal carrier under the PCB, there's a good chance your module won't work.
10) make sure capacitors with a +/- designation are polarized properly. LEDs too. Resistors can go in either direction, same with most of your capacitors - orange drops, mica and ceramics can go either way. The ones that look like little barrels are usually polarized though.
11) measure twice, cut once.
