That will be a job and a half in itself. Seats out, peel bach the leather trim, etc.
My recommendation would be to try fitting a panhard rod first. It will help the handling too.
You should be able to get in and clearance the casting with a small die grinder and a carbide burr from underneath
It won't be pretty but it will work
Use wd40 or candle wax on the burr to prevent clogging
And wear eye protection
Take it from someone who knows, having metal drilled out of your eye is not fun
Simon @ SiFab.co.uk