Removing Guide Pins on Bottom Bellhousing

[Old26Buick 14]

I need to remove the guide pins on Bottom of 27 Standard bellhousing. The ones that match bottom half of bellhousing. I did a stupid thing, I forgot to put bottom bellhousing on, now I have trans and rear end all bolted up. Do these pins screw in or driven in?? Should I just try to drill out and get new pins?

Thanks