Hi,
The full instructions are located here:
http://www.cisco.com/en/US/products/ps6120/products_configuration_guide_chapter09186a008063b3d6.html
It would also be advisable to read the release notes before attempting an upgrade. In fact, reading the release notes should be compulsory reading for any upgrade.
Failure to read the release notes is probably the single most common reason for upgrade failures, such as the following:
o The new software requires more flash or ram than is currently installed
o A feature is no longer supported (e.g. authenticated header in ipsec)
o A feature which previously worked fine is now listed as a "caveat"...
HTH
Andrew.
