Well, I loaded my backup. Yet it still says I cannot change it because it might have a balance in prior year (it does not), current year (it does), or future year (it does not).

Exact error message is:
This account has an Opening balance or a Closing amount in a Prior Vear, the Current Vear or Next Vear.
The account type cannot be changed.

Can I just do a Journal Entry into an account that is an Income Statement, and then those accounts would have a zero balance and then could I just delete them? There are 4 accounts.