I recently purchased a Lazy Wolf trigger from HKParts.net for my VP9 as the stock trigger kept pinching my finger. It came with no installation instructions and the link to a video by Lazy Wolf no longer exists. e-mails to both HKParts and Lazy Wolf have gone into a black hole. The usual searches on YouTube and HKPro forum turned up nothing.
Can anyone point me to a video or detailed instructions on how to install what is marketed as a “drop in trigger” (it ain’t BTW).
My opinion: Use the stock trigger. Use it enough, your finger will adapt.
I say this as the owner of multiple VP9’s, one of which I had an hkparts.net trigger return spring changed on (range use only). I mostly do my own 'smithing. Even the actual gunsmith had difficulties.
I think the black hole may be for a reason, nobody wants to dive into it lol
Working on the internals of that thing is nothing like working on a Glock. Good luck. Consider shipping it to a gunsmith who can do it professionally.
I would suggest altering your finger and leave the trigger stock.
Does Lazy Wolf Guns trigger have a special procedure or it’s assembled same way as other triggers?
It’s advertised as a drop in trigger with an Allen screw adjustment for overtravel. Other than the adjustment for overtravel, and the color of the dongle, it looks like the stock trigger. The challenge is keeping track of the tiny parts that must be removed and reassembled and dealing with the stock trigger return spring, which is hard to re-install.
OK. That was I wanted to know. I never used Lazy Wolf trigger but looks this will be the same challenge as with other VP9 triggers 
Here you have videos I’ve been using for myself:
And these are the PDF files I downloaded from H&K Forum some time ago:
VP9 Part 1 - Frame Disassembly.pdf (4.2 MB)
VP9 Part 2 - Frame Reassembly.pdf (4.1 MB)
Hopefully these will help you.
Thanks much!