@plugcrazy
Not difficult! ( On V1.3 Sheevaplug which I have)
Open Sheeva plug case
Unplug 5v connector on sheeva SOC PCB. (from mains PSU +5V output)
Remove Mains PSU, (just unclip ally box), and mains figure 8 socket
Feed POE 5V from POE splitting / conditioning device, through hole where mains figure 8 socket was removed
Connect POE 5v to Sheeva pcb, (Would need to obtain suitable +5v connector. standard part, unless you chop the old one off the mains PSU o/p cable and join it to POE 5v)
Here are pictures of V1.3 pcb:-
http://plugcomputer.org/plugforum/index.php?topic=683.msg4148#msg4148On last (4th) image Power connector is 4 pin top right, pins are paralleled up for current capability
Job done!
P