How do I reinstall subledgers for reconfigured operating unit, LE and Ledgers with new acct calendar

My company has changed their accounting fiscal year and I need to update our current configuration to the new fiscal year. Our current configuration includes: legal entity, primary, secondary ledgers, operating unit, payables and cash management that use the original accounting calendar.

To implement the new accounting fiscal year, I created a new accounting calendar. Then I configured a new legal entity, primary ledger with new calendar and secondary ledgers. It's my understanding that I cannot assign the newly configured legal entity and primary ledger to the existing operating unit and subledgers. My only option is to create a new operating unit and reinstall subledgers, correct? Can you help me with the configurations steps needed to setup a new operating unit, reinstall subledgers and data conversion? Can you also help with converting general ledger balances ? Thank you in advance for your