Visiting Terminal 1 while in transit at HKIA

We have a five hour layover in the Hong Kong airport while flying from Manila to Los Angeles. We'd like to visit the IMAX Theatre in Terminal 1, but we are unsure about:

1) the best/quickest way to get there
2) what security issues will be involved (do we need to have passports stamped, etc)

Any last minute help that can be offered would be great! Thanks.