First of all LJ you are looking for a miracle and that is not likely to happen. Everybody and I do mean EVERYBODY comes across a hurdle somewhere with something. The most common is working on cars. Believe me, I can tell you some stories.
Does it or should it preclude you from doing something or in this case modding lights? Absolutely not! The very first key to success is recognizing one's weakness and strong points.
From I have garnered on this site, soldering resistors is a very small part of the equation. There are many mny more aspects, and from the sounds of it you are quite proficiant at some of them. I will not get into some of the things (not flashlight related) that took me years to master but I will tell you that until the "light went off" and I finnaly figured out "how" I commssioned others. It wasn't out of laziness but the savings of time and money.
In relation to modding lights, I too am learning to solder...and have been for years..in other words I am lousy at it. Lol. As of yet I haven't modded or even built a light BUT for the time being I am planning on buying some drivers from RMM (his charges to modify are minimal) that will be configured the way I want and need. That way I don't ruin anything and still get what I want. For practice I will work on the pulled drivers. The other alternative to soldering is the use of FET drivers (as already mentioned).
There is no need to get discouraged or disgusted. Just skip that part (soldering) for now and put your energy where it helps you and gives you a sense of accomplishment whe you turn on that super bright light :)
Good luck and enjoy your hobby ;)