Thanks Pilotdog68, at least I have all the tools and some wire. I do have decent technical skills and can solder ok so I was looking jump in to something a little more challenging. I am an aircraft technician by trade so I am not afraid of some complexity. I Have pulled a few lights apart and put them back together and I have done a couple drop ins so I am looking to take it a step further. Of the lights I mentioned earlier, which one would you say is the easiest to mod?
Dog 
already mentioned tools, I would add multimeter, some basic model will do the job for starters.
As per light, Convoy C8 is very enjoyable to assemble, I would recommend ordering regular XM-L2 version with 8xAMC chips and then replace the emitter with XP-G2 on a copper star, it is easy to do, not much can go wrong and you will be satisfied, not much work to get good thrower/results, it will give you an incentive for more complicated stuff. You could even try to do a XP-G2 dedoming before implanting into C8 but that can be a tricky business if you do it for the first time.
Well I don’t actually have any of those, but from pictures I’ve seen both the small sun and yezl look fairly easy. The yezl might be a bit more difficult because it has an e-switch you must contend with.
Do not own the light but what I saw, zy-t13 might be a good candidate, only resistor mode + dedoming will make it a good thrower!
More info by AlexGT here post no. 47.
oooooh I hadn’t seen that one before. I just might get one to put an XHP in.
Oddly enough, the TN31 is one of the easiest lights to mod by far.
The TN31 and the K40 are very similar lights, and I’ve done a write up here: Supbeam K40 Mod thread
Gasoline is also handy to have around if you’re planning on de-doming, as the razor method can be challenging at first.
It was a very popular light in times when wallbuy had exceptional deals (about a year ago, or so) cheap (was), easy to modify, throws like significantly more expensive lights…
That looks like a good one. Thanks for the info!
Thanks, I’ll definately check out your write up! I have done some reading up on de doming with gasoline and I definately want to try it. As far as the TN31, I have done some research and it seems fairly easy to mod but as I mentioned in the OP, I would rather tinker with a cheaper light first. That’s just me 
zy-t13 + XHP70 6V + zener nanjg 105C with some extra AMC chips and custom firmware, that could be interesting 4000+ lumens project 
What about the insulating tape, Kapton or something like that.
Yep, kapton tape is a must
I’ll put it on the list, thanks.
Sandpaper and a metal file come in handy too
I’ve also found that having a small pick can be extremely useful for lifting up stars and drivers.
Something like this: 4 way pick
Besides the good suggestions already made, here are a few of my useful oddball items.
I use my butane torch quite a bit to reflow Noctigon boards to brass pills, and to solder adapter sleeves or heatsinks in place.
A honeycomb ceramic plate for when I’m heating up bigger pieces so they don’t lose much heat to what they’re sitting on. (small and cheap, very nice)
Silver bearing solder for pill modifications. Reduces the possibility of things moving around when I reflow the MCPCB onto the pill (for which I generally use regular 63/37 solder)
A machinist clamp and small bench vise to securely hold the pills while working on them (soldering or assembling). Spending money on a good one removes a lot of frustration. Cheap ones are sloppy and a pain to handle. (I made mine in shop class, very tight tolerances )
A headband style magnifying visor can be useful.
Lots of q-tips and 91% isopropyl alcohol for cleaning up flux, thermal paste, etc.
Nyogel for sliding interfaces, O-rings, and zooming threads. Noalox for threads that are current carrying.
Eyeglass cleaning wipes to clean lenses before assembly.
A couple of twin tip Sharpies for reducing reflections.
Glow in the dark spray paint.
A hammer and vise with a flat area so I can hammer on copper. With the addition of a decent set of sockets and good snips making accurately sized copper rings or sleeves from round wire or sheet is a breeze. A pair needle nose pliers that have been sanded to remove the corners and teeth is useful for final tweaking without kinking or damaging the copper piece.
A couple of cheap nitrile O-ring sets to adjust focus points and fit.
I like 18ga silicone wire, I have yet to find a light I can’t fish it through, and makes a good spring jumper.
R100 and R330 resistors for sense resistor modding. This combination covers lots of bases. The ability to do .05, .0767, .1, .165, or .33 ohms with only 1 or 2 resistors works decently with a lot of drivers.
Third hands
I asked my dentist about dental picks and they gave me the old ones for free. This is a great tool to have.
You’ll want to get a tub or two of this stuff. I go through it in a hurry, especially when working on small lights! 
Definately, do you know where I can get a good deal on it?
I really like this idea! Wow, it sure is going to take a while to gather all these items. I have most of the tools mentioned here but will need to build up the consumables and common components