Did my CDti last weekish took about 45 mins in total with a tea break
Undo top of Dip stick and swing out of the way to get access. battery lead off..
I pulled some rubber pipes up & out of the way and tied them to the EGR for a bit more room.
Best not to Drop anything !!!!!
Use a small socket set with extensions to remove the big lead, the 3 cover nuts and the 4 fixings for the regulator.
it will be a bit grubby in there .
Then all depending on how good the alternator commutator is, and whether brushes will sort it ?
Either a whole new regulator pack or re solder in a pair of brushes from Ebay at about £3.
C