Muffler Heatshield

Hi folks just posting this as I am having problems here. The heatshield bolts have broken off, I can't figure out how they all fell off but they did and now the heat shield was laying right on top of the muffler. I have been able to twist it off around the muffler but I am stumped on how to reinstall any bolts since they old bolts have broken off and I can't even get to them to drill them out unless the muffler was right off. Any suggestions?

Oh and is it ok to drive back and forth to work, only 10 minutes away without the heatshield just until tomorrow evening?