This has been 1 of the most popular upgrades for aap01, notwithstanding a guide on installation.
Figured i'd share what i know after 3 hrs of fiddling around and some youtube vid ref of other triggers (may try your luck looking for cowcow g series trigger install) :
1. checkout full disassemble of aap01 on youtube. Waldo has an excellent video.
2. Understand the cowcow parts: 2x long fixing screws, 1x tiny adjustment screws, 1x tiny spring
3. safety spring - under the trigger where the safety goes onto, there's a tiny round recess, that is where the spring goes
4. safety - carefully press the safety (where theres a cutout) facing the spring and screw 1 of the long screw on. this is quite challenging. dont lose the spring!
5. trigger bar - fix with 2nd long screw. easy. i think screw in from any sides will be the same.
6. reassemble following Waldo's.
7. before putting the top on, pull the trigger slowly until u see a tiny notched/curved out area (see image) and scew the tiny screw in, tighten or loosen to your taste and pleasure.
8. note that short trigger pull will render the trigger safety and the pistol safety useless.