If you end up having to drill it out (ugh!), pressurize the galley from
somewhere else with shop air so that any chips get blown back to you.

I'm not a fan of EZ-outs for something that is extra tight, as you may
end up distorting the threads in the case.

Penetratiung lubes etc won't penetrate the threads if there is pipe
dope in them. Instead the lube will probably get on the wrenching
surfaces & make a stripout that much more likely.

My read at least...... Still - good luck!
nrp