Mass update General Ledger hierarchies

Is there a way to mass update General Ledger hierarchies?

Normally you change things one at a time using the Account Hierarchy Manager.

Nav Path:  Setup --> Accounts --> Manager

While you can export the hierarchy, I don't see any way to import one. I have found no API's either.

We would like to make extensive changes to the hierarchy without having to drop and drag items one at a time.

Thanks.