Thinking about a JB4, would like to know what is required to run it

Hi, I am thinking about installing the JB4 system on my 335i. I would like to know if I need any other mods to just run the jb4 tuner or if i can just run the tuner with stock internals. Also, I would like to know if anyone has had any problems and if the tune had ruined their car in any way.

Thanks

Thinking about a JB4, would like to know what is required to run it