Assistance with 'Prepare Electronic Pay' file

Hi, I'm hoping someone can assist me with how to remove an employee pay from the 'Prepare Electronic Payments' tab. They are no longer with the company and had mistakenly been put through the pay run with our other employees. Thankfully i noticed before creating the bank file for payment. i have reversed the pay but now can seem to figure out how to remove the original plus the reversal from the 'PEP' tab. I attempted to do it again but only ended up with 2 reversals now sitting in there along with the original. It's just a bit of a pain as i have to be sure the original payment isn't ticked each week i do pay runs and wind up paying a terminated employee. I asked my accountant to help but it was beyond them also. Is someone one able to step me through where I'm going wrong?