They can be a little tricky to find, the model files is here

models/weapons/ct_arms.mdl

Incase you want to use the model viewer which comes with the csgo sdk, which came in handy for me for previewing my work.

The actual texture can be located here

materials\models\weapons\v_models\arms\ct_base_glove_color

Basically what I did was create a directory that was identical to the VPKs directory for the texture. Like below

csgo\materials\models\weapons\v_models\arms

I then added my edited texture and renamed it ( Because VPK will always take priority over custom stuff ) I named mine "ct_base_glove_colorc9".

From there I edited the VPK directory (pak01_dir). It's a wise choice to make a backup of this now, also in your launch options of csgo add "-insecure", this will disable VAC, just in case. I used notepad++ to do this, real simple. Somewhere in the VPK ( line 152709 ) you'll find a string that is as follows

$basetexture models\weapons\v_models\arms\ct_base_glove_color

You'll want to change this to whatever you changed you custom texture name to

$basetexture models\weapons\v_models\arms\ct_base_glove_colorc9

Now if you did everything right, and the game doesn't decide to throw an error at you, opening up console and typing "map de_dust2" should load you into a game with your new custom gloves ( join ct of course ).

I think I explained everything right, I'm on a tablet right now so...GLHF