No, Admins cannot delete accrual leave entitlements.
There is an option to change and update these entitlements by going to Leave --> Entitlements --> Entitlement List.
This page allows for you to search for an employee to correct, once selected, please select on the pencil icon to edit/remove these entitlements.
Once you are satisfied with the changed accrual number, please be sure to save on the bottom right.
Refer the following article