Relearning & blocking security policy

Hi guys, we have requirement from client that they have already created the policies in learning mode however policy builder has been stopped.This task has been done four month back now customer has requirement that fine tune again this policies with new request learned as some changes has been done in the applications now.

Can you please suggest me how to proceed with that for fine tuning & then blocking.what will be the important things are required to keep in minds.

Will appreciate your quick responses.

Thanks..