How to change the tensioner and deflector pulley on a BMW 5, 7, X5 series N62 engine 

Yiu have the accent of Arnold :)

They say the bolt is a non-reusable type and prone to snap if reused - are you confident it's OK to reuse? Also, mine looks to have a separate A/C belt - would you replace that tensioner too or does that one not matter?

Do you have to replace the old tensioner bolt with new bolr?

Did you disconnect the battery first or no ??