Popular options are:

Irwin bolt grips
Dremel cutting off, and replacing studs if required
Chiseling off at correct angle

All of the above is aided by a good soak in penetrating oil

/ plug gas in the days leading up to attempted removal!

Oil leak is more often from the cam chain tensioner, which is on that side of the engine, just below the cam cover

- it does indeed use instant gasket out of the factory

- so is nice and easy to redo

- two 10mm bolts to remove the plate, clean up, new gasket, bolt up, done.
