How can I edit suggested buyers assigned to open requisitions?

My team is attempting to resolve constraints related to PDRT and one the employees has the following constraint: "iProcurement: This person is a suggested buyer assigned to open requisitions. Reassign the requisitions."

I am able to find requisitions where the employee was a buyer via Purchasing Buyer -> Requisitions. There seem to be a lot of open requisitions, but I'm unsure how to update them and also do it efficiently since there are a lot of them. Could someone point me in the right direction?

Thanks!