Pull the battery. It's on the sticker underneath.
If you're not sure on how to open that compartment, you HAVE to open the slider, let it tilt, and the fingnail slot is tehn revealed to pull the cover off.
The MSID on any Sprint device is not actually on the device itself but would be given by Sprint. Sprint devices have two #'s used in programing the device so that you can make calls. If you need the MSID you will need to call into Sprint customer care so they number can be provided.