Headlight switch replacement 64 malibu

[oldguy64malibu]

Anybody know how to remove frozen retaining nut holding switch in dash panel ?
This is the nut with the two dimples. I have tried penetrating oil and a small punch and ball peen hammer but it will not budge. If I have to drill out the retaining nut where can I get another one ?
Thank you.
Local DQ is now open for the season and its warm enough to put the top down and Grand kids are visiting for spring break, yahoo.