Two methods and one comment. The comment is that you'll want to go back to 6.0(4), not 6.0(2), for operational use.
[edit]The following works generically on the standalone sensors... I missed that this was a question for the AIP-SSM. It should still work on the AIP-SSM with adjustments for the "alien in the box" I/O.
To recover, a reimage using one of the tftp-able images (or a boot CD if you have a 4235/4250 sensor) is the gold standard for going backwards. You'll lose your configuration when you do so and need to run setup again.
The other way, and officially this is unsupported for "downgrades" but it works 98% of the time, is to load the -r- recovery image (IPS-K9-r-1.1-a-6.0-4-E1.pkg) and then do a "recover application partition" from the "conf t" level. This will reimage your sensor and preserve the basic network setup. You'll still lose signature customizations and passwords will be reset to factory default, but the network setup is preserved, so you can do this remotely.
