Here are the steps to upgrade it:
- Copy the .bin file from the TFTP server to both Sups (Active and Standby)
 
          copy source_device:source_filename bootflash:target_filename
- Change the boot system command
 
- Change the config register
 
no boot system flash bootflash:c6msfc2-jsv-mz.121-8a.E5
wr mem
boot system flash bootflash:c6msfc2-jsv-mz.121-8a.E6
wr mem
- Reload the Standby Sup
 
config-register 0x2102
wr mem
          redundancy reload peer
- Failover the Sup
 
          redundancy force-switchover