upgrade to iLife06 and external hard drive

Help I just upgraded all 3 macs to iLife 06 but forgot about pics, movies and music on my external hard drive. Cannot access those from external hard drive Can I re-install 05 so I can get my stuff off external drive? Then re-install 06. Dont want to create more of a prob? Thanks

power book g4,iMac,iBook Mac OS X (10.4.8) all are 10.4.8