If you go to intraCX/Flight Crew Team/Fleet e-library there's a step by step guide under All Fleets/syncing company edocs with iPad.
If you're on a Boeing fleet they have a fleet specific dropbox you can sync with that has all the updated manuals plus a bunch of other useful stuff. This is the easiest way and means you don't have to go through the palaver of getting the edocs synced on your own computer.