All you should need to do is the following:
Interface serial0/0
service-module t1 clock source line [internal]
service-module t1 timeslots 1-24 speed 64
which clock source you use, i.e. internal or line, depends who is providing your clocking currently. If it's a Full TI, I would suggest it may be the T1 provider - thus your clocking should be set to line.