Do a backup Store remotely if possible (XBK)
Ensure the format of the new T-1 is the same as the old
Disable the T-1 before removing, then once new T-1 connected enable.
Check counters
Check clocking to make sure you are not in freerun
Make multiple test calls to various area codes in order to make sure provisioning is correct on the vendors side.
Hopefully that will take care of what you need, though there may be other steps some people would recommend.