Delete an Account Balance on the Balance Sheet
If you need to remove an account balance that is showing on your balance sheet, you can either delete the supporting journal entries for that account or make adjusting entries to nullify the current total.
1) To delete the journal entries, click the Account Balance value on the Balance Sheet or search for entries with the Ledger -> Reports -> Account Activity report. Click the Voucher link for entries you want to purge. You can then click either Cancel or Unpost this Voucher. If you click to unpost the voucher, you can then click Edit and then Delete to get rid of the entry.
If you find you are not able to cancel or delete a GL entry, this may be because doing so is blocked for GL entries that did not originate as direct journal entries. See the setting Admin -> Billing -> Company Options -> General -> Block Non Direct GL Entry Editing. For non direct GL entries (those from invoices, vendor bills, payroll, etc.), it is best to reverse those from the original module itself. For example void payments, cancel invoices, delete vendor bills, void checks, etc. to reverse the GL activity for that type of data.
2) To make an adjusting entry go to Ledger -> Journal Entries -> New Journal Entry.