Cummins 8.3L mechanical.
I have changed my alternator twice. The belt four times.
But.... I have a side radiator so have access to the belt and alternator from the rear.
The belt takes about 5 minutes and is just looping the belt around the pulleys with the tension pully held relaxed with a socket wrench. I always carry a spare belt.
The alternator will take @20 minutes to remove, once you identify the right sockets sizes. It requires the belt be removed and then two bolts as I recall. The wires will need removal also.
I found my Cummins engine manual to be quite helpful since it has pictures of all repair and replace procedures.
