service mode and cam locking tools

[maxrs4]

i think im doing my cambelt on the audi this weekend, never done it so looking for advice!!
, i have seen a locking pin kit and a bar looking device that looks like it goes between the two cams?

my friend said he will be bring the lokcin tool home but what should i expect?!
also i know it has to be in "service mode" how do i get it there!!?

thanks

[Virdee Autos]

REmove front bumper
Remove undertray
REmove bolts holding front lock carrier, and bring into service position.