hgrimberg go to
http://colorado4wheel.com/manuals/Jeep/KJ/ and download copies of BOTH the 05 and 06 FSMs (the 05 lacks cooling data and diagnostics but has illustration keys while the 06 is the reverse). Then take a look at the illustration on page 7-31 of the 06 manual. My #s are keyed to that drawing.
The clutched alternator pulley can be removed (using the OEM special tool or some have gotten it off with an appropriate size allen socket and impact wrench) and replaced BUT the replacement must be up to factory specs for the diesel engine (see
http://idparts.com/catalog/index.php?cP ... ef6v1rhvi0). A similar size gasser clutched pulley or a "reactive" pulley simply won't stand the strain. Any wobble in that pulley gets directly transmitted to the serpentine belt down to the belt tensioner and can relatively quickly cause the tensioner to fail.
Here in the US some replace just the pulley while others have been able to obtain an inexpensive lifetime warranty alternator with the proper pulley from like Autozone. I see your signature says you have a "Cherokee Liberty (aka KJ)" which indicates you are not in the US. If that's the case I don't know whether sourcing a pulley vs. an alternator is the better option.