This should be informative enough for a beginner, but it's a relatively tricky mod. Use the proper tools, and be patient. I've seen many people struggle with this mod.
It mainly applies to the 1/4" pro sound kits we will soon be carrying, but is the same general idea for other 1/4" jacks, if you don't want to buy the kit.
http://www.asmelectronics.org/2011/11/1 orial.html
To those reading this thread months/years from now: Broken link? Try going directly to asmelectronics.org and going to the "tutorials" section. If my website URL has for some reason changed since then, go to my profile to find the new one.
Cheers!