Adding Expansion Module to Active/Standby Cisco ASA

Hello Everyone,

I need to add an expansion module to a pair of Cisco ASA 5585's in a Active/Standby failover configuration. My initial plan is below.

1. Power down standby/secondary unit and install the module.
2. Bring the standby unit online and promote the device to active.
   
3. Repeat the steps for the primary/active unit.
   

My worry is that step 2 will cause a failure when the secondary tries to sync with the primary. This would be due to the fact that the devices will not match. If this is the case, what is the recommended procedure to doing this? Sadly, I do not have 5585's in the my lab or else I could test this.

Thanks!