According to the current data sheet you just need to insert a 10G linecard. However, depending on your MSM, you might not be able to run all ports at wire speed (page 6, MSM table, "Slot Capacity").
Can't say anything about the required firmware though; always using the latest 188.8.131.52 release. Hardware support should be listed in the EXOS release notes.
The MSM 48 has the same performance as the MSM-48C and can be used with a 10G module. There is information on SW and HW matrix on e-support that will list the minimum SW versions needed. The older 10G modules go back to 12.1 code and the newer 8900 modules go back to 12.4
To Ron's point above if you use a 8900 module you will not get all of the bandwidth as you would if you had a MSM128.
If you use the 4 port 10G module you should be ok as long as the modules are supported in the SW.
Hope that helps