Steps to Upgrade from 2008 Server and DVLS 5.1.1.0 to 2016 Server and 6.0.2.0

Hello,

we had problems when i made an upgrade from 5.1.1.0 to v6 on our 2008 server.
A colleague helped remote but we had to revert everything and we couldn't find what caused the problem nobody was able to connect to the server.
So he wanted to look for the issue and give me feedback regarding a problem wirh 2008 server?!
I managed to get a 2016 server VM for testing and need help for transfering everything to the new environment...