There are the steps for completely clearing and redoing a system posted period:
1. Open General Ledger area
2. Confirm you have no general journals posted in the period you wish to reset.
3. If you do, Reverse post them.
4. Confirm you have no system journals posted in the period you wish to reset.
5. If you do, Reverse post them.
6. Then delete them.
7. From the menu select Record|Properties
8. Click on Special tab.
9. Next to "Clear Period No" enter the number of your period you wish to reset.
10. Press Clear
IMPORTANT: If you are clearing period 1, you will be prompted whether to clear your opening balances. DO NOT clear your opening balances.
11. Run Trial balance and confirm all activity for reset period is zero. But if you are resetting period 1, you should see only your opening balances.
12. Run End Period Wizard for period you have just cleared.
13. If you had reversed general journals as per step (3), post them again.
You have now redone the entire period.