Removing read-only Java system files on Mac?

Just installed and ran avast! for the first time. Full system scan seemed to be effective.

However, when I mounted and scanned a .dmg of an older boot disk that ran OSX 10.4.11, there were lots of infected files found in the user/Library/Caches/Java and /Java Applets. None of these can be moved to the Chest because they are “read-only system files.”

I’m sure there’s a work-around for this but I’m not finding any info. Can anyone help?

Running avast! v8.0 under OSX 10.8.5 on a 2.3ghz MacBook Pro (i7). Thanks!

Please ask here: http://forum.avast.com/index.php?board=5.0