Also I read that changing the hdd is not a too simple tast. Then again I guess it would not be more difficult than replacing the hdd on Powerbook (which was a bit fiddly, but okay). Anyone already swapped the hdd? Unfortunately I am a bit short on time next days/weeks, dunno when I will do the hdd replacement and actual system migration.
I used this guide iMAC-ifixit
AmigaOS: Pegasos II, Sam440ep-flex, Micro A1-C, AmigaOneX1000
MorphOS: Pegasos II, Powerbook G4, iMac G5, Powermac G5 Quad