Hi,
The modules are hot swap-able but before replacing it make sure to make a good copy of the running config. Also, make sure the current version of your IOS support the new modules. Here is hardware installation note:
To install modules in a Catalyst 4500 series switch, follow these steps:
tep 1 Take the necessary precautions to prevent ESD damage. Wear a grounded ESD wrist strap while handling the modules, and keep them in ESD-protective bags when they are not installed in a chassis.
Step 2 Choose a slot for the new module.
Verify that you have enough clearance for any interface equipment that you are connecting directly to the switching module ports.
Step 3 Loosen the captive installation screws that secure the existing module or the blank module filler plate in the slot you want to use.
Step 4 Remove the existing module and immediately place it on an antistatic mat or in an antistatic bag. If you are removing a blank module filler plate, set the blank module filler plate aside for future use.
Link:
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/hardware/configuration/notes/OL_25315.html
HTH
