Need help from a pro. flat roof leaking

I have a flat roof over my garage (tar and rock) that is leaking. I have removed all of the rocks that could be removed but quite a few are imbedded in the tar. The tar is old and brittle with many cracks. Any suggestions on how to prepare a flat roof like this. I have been told peel and stick and elastomeric roofing? Maybe some advice from someone who has dealt with this type of roof before.

I say install a new clean substrate and a waterproofing membrane system over that, if possible. If it is too badly cracked up, best to do it anew.

tear it off and start new.if your roof is cracked,chances are there is bad decking underneath.

Tear it off to the bare wood, inspect the existing deck and torch apply a bituminous membrane. Fully adhered EPDM is also a possible option. I like Firestone products myself. I don’t do re-covers at all.