This is somewhat a loosly based toutorial of how to install a ragnarok chip with 5 remappible tac switches. If u buy a kit from vikingdigital.com they have downloadable pdfs on all the installation and prep work. Though this is nice Its not very specific so I posted a little walkthrough of a build I did. I don't feel like re posting and downloading a bunch of pics again so I will leave a link to the Viking forums where I posted my walkthrough. I encourage others to give it a shot.
The ragnarok chip has been updated so I can now have up to 5 remmapible tacs and the price is right to move! This now blows all other mod chips on the market out of the water. Console customs has nothing on the new ragnarok chip.
So enough blabering on, below is the link to my build and if u are serious about doing this my build will help u out in all the gray areas in the Vikings pdfs.
https://forums.vikingdigital.com/threads/sick-ps4-rag.6414/