Although you are not able to delete an accrual entry, you can add a new accrual entry to offset the balance.
As an example, if you accidentally added a duplicate accrual entry in the amount of 40 hours and need to remove 40 hours, you would do so by visiting the affected employees profile and select Time Off from the left hand menu.
Once at the Time Off section, you'll want to select +Add Time Off Accrual Entry.
On the following page, you'll need to select the time off type you want to adjust, the date of the entry, how many hours to subtract and any notes. Because you are wanting to deduct a balance, you will want to enter a negative number - in this case it would be -40.
Once done, you can view the history for that time off type and will see the deducted entry as well as the employees new balance.