How to change mech advance on this distributor?

I tell you how I'd do it if I JUST HAD to run that distributor. I'd drill and tap each tab and use a long allen headed set screw with a lock nut on it to adjust the mechanical advance. .........but then, I wouldn't use that distributor. LOL
Ya good idea. $100 440 Source distributor. Get what you pay for I guess. MSD ready to run looking real good right now!