a multimeter, tweezers, circlip pliers, soldering iron and helping hands are enough to do what I would consider an advanced driver swap.
I have done mods with nothing other than my van seat, mole grips, needle nose pliers and soldering gun, its as much how inventive/determined/knowledgeable you are tbh as how many tools you have.
have a good look through the modding section, read lots of old lumens, comfy chairs, rufusbducks, racer86’s, tom e’s and relics posts as you can and you’ll soon pick the tech up, then move on to pilotptks posts, texaspyros, hkjs etc to help build, mix this up with johnnymac and foys reviews to lighten the load and chicago x’s x mods and you’ll have built an impressive knowledge base to put your tools into use.
the most important thing is to get a cheap light like a c8, strip it, use it as a base, do a driver swap, an emitter swap, just get it working with something else in it, don’t worry about refinement, just getting it going, that’ll teach you more than anything else.
find ouchyfoots profile and look at his posts, he asked lots of questions that’ll be helpful to you.
good luck and don’t give up, that’s the key, just having the determination to succeed, you’ll soon figure out the tools you need.