New version is coming today with documentation https://forum.decred.org/threads/0-3-0-release-scheduled-for-monday-aug-15-2016.3956/
Seed restore is not yet usable in Paymetheus. At this time you would have to create a transaction that moves value from another wallet into Paymetheus. You can track this GitHub issue for updates on the availability of this feature: https://github.com/decred/Paymetheus/issues/158