So what grease does everyone prefer for thread lube? What about adhesives, what uv glue are the experienced folks suggesting? Third of all, any tools or supplies I should get (other than the obvious ones like soldering iron, magnifying lens, headache meds, etc…lol) before starting on my light modding journey?
...the search feature. Whodathunkit! Lol. Thanks brother, now i got some reading material.
welcome 
modding (LED swaping) is very rewarding
here is a modding sequence in photos, to give you some ideas:
Do you have a specific light in mind, that you want to change the LED on?
Some lights are very difficult to open, Olights for example, and they use XM footprint instead of 219b type so the mcpcb needs changing
here is an Olight mod, with pictures:
THREAD LUBE: Super Lube & Nyogel (I suggest looking up the various types for different applications)
ADHESIVES: Depends upon the application but consider having available various strength Threadlockers, Thermal Adhesive, Reg Super Glue and so on...
UV GLUE: For Trit vial installation? I use Super Glue's version of Optically Pure UV Adhesive
TOOLS: various Vise styles including Panavise, a 3rd Hand device (from a cheap Harbor Freight type up to a good multi-arm product such as Quad Hands), a variety of surgical-style hand tools including forceps, tweezers, probes, picks, etc., a Spudger, an inexpensive Hot Plate for Reflowing LEDs, mini Pliers & Wire/Flush Cutters, a pair of good Strap Wrenches, a variety of mini Scrub Brushes, Q-Tips, Safety Glasses, Quality Overhead Lighting, Lighted Magnifier Lamp, a Good Headlamp, an Anti-Static Strap for working with delicate Electronics, and absolutely a Digital Multimeter, etc. The list will naturally grow with your challenges, experiences and confidence, so don't feel it's necessary to obtain everything upfront.
CONSUMABLES: Solder, Solder Paste, Flux, Isopropyl Alcohol, Various Cleaning/Removal solvents, Purified Water, Blue Workshop paper towels, old rags, Compressed Air
Regarding reflows. I don’t own a hot plate. I’ve had no problems using a heat gun to reflow LEDs and it is also very useful for removing glued-on bezels.
If you’re trying to maintain a budget, I’d suggest buying a heat gun first and if that doesn’t work for you on reflow jobs then consider a hot plate. The former is a versatile tool while the latter is pretty much single purpose.
No doubt that my $40 Porter Cable heat gun has been a great additional tool to have available, especially for getting adhesives to release. I don't want to overwhelm a new modder by including every tool on my workbench, especially those that aren't used as regularly in "my experience".
As for reflowing LEDs, I've tried multiple methods over the years, most of which will get an LED to adhere to the MCPCB, but not necessarily having it seat properly on the pads. However, I've personally found that when used along with a Digital IR Thermometer to monitor the heat ramping process, that my $20 Oster hotplate allows me to stay within the LED manufacturer's recommended reflow profile with repeatable success every time. This process is recommended by manufacturers for a reason, which is to avoid "shocking" the LED, which compromises luminosity.
I'm not going to suggest anyone's method of doing things is wrong or inferior, that's for you to determine.
Good points, KnotSoMuch. I haven’t done any research on hot plates and didn’t realize they could be so affordable. A $20 one that works well sounds like a good investment and eliminates lots of potential frustration.
But for a new modder I’d suggest not even bothering with reflows at first. You can find just about any LED pre mounted on an MCPCB. I started modding, like probably many people, on S2+ and C8 hosts. I’m still a novice and did my first heat gun reflows recently on small aa and aaa lights out of necessity - I didn’t have any MCPCBs that small but did have LEDs on 16mm MCPCBs I could swap over.
My hotplate is an old electric skillet that the family no longer uses. It heats up to 425F which is just hot enough to reflow LEDs using typical soldering paste: Mechanic Solder Paste. And as a bonus, it smells like pancakes when I use it!
Some LEDs are mounted using non-leaded solder, so in order to remove them, I put my soldering iron at 700F on the positive or negative pad and remove the LEDs when it gets hot enough.
Agreed there are a lot of LEDs that are available pre-mounted on MCPCBs. It’s amazing the variety we have to choose from. But sometimes you still need to reflow since what you want is not available. For example, I wanted a triple 4500K Nichia 519A LEDs, but Convoy only sells them as a single. So I bought a triple MCPCB from MTN, bought the bare LEDs, and reflowed them on my skillet.
See, shows how new I am, I assumed it was all done with a soldering iron. I've learned a ton already, yall keep discussing, I'm eating popcorn and taking notes!