Replace the VSX primary or the VSX secondary with the following steps.
config
Switch(config)# interface 1/1/1-1/1/52 shutdown
NOTE
Restoring firmware is required only if replacing the primary VSX member. Otherwise, restore the configuration because VSX sync would force automatic software upgrade on secondary member.
The switch should now enable the VSX ports. Once VSX sync is completed, all ports should get enabled after hold-down timer has expired.
NOTE
If replacing the secondary member and a software upgrade was not done prior to enabling the ports, there will be a reboot on the secondary unit after it has detected the primary VSX member and received new software from it before normal ports would come up.