Are you at an airline? Your POI can do it.

If your local FSDO isn't answering, try a neighboring one. You could also go through the DPE list to see if any of them can do it; will probably cost some $, but well worth it in my opinion.

As for the process itself, it's very simple. Unless IACRA has had the functionality added, you'll have to fill out a paper 8710-1, but just bring it along with your logbooks and a photo ID and a temp cert with the restriction removed should be issued to you on the spot.