Dump the databases on the current production system.
Before the upgrade, run dbcc commands (checktable, checkalloc, checkcatalog).
Alter the sybsystemprocs database.
Perform a pre-upgrade verification.
Upgrade the production system to Release 12.5.
Run dbcc commands (checktable, checkalloc, checkcatalog) on the Release 12.5 databases. Be sure to verify the dbcc log and error log.
“Baseline” the Release 12.5 configuration on the production system.
Perform user testing and verification.