OMG!

My Dell T7610 is booting up blank as I accidently turned on Secure Boot w/ UEFI.  I need to turn it off, but the video is gone.  Can someone please help?  Is there a way to reset the BIOS?  Can someone give me instructions to turn off secure boot with key instructions so that I can turn it off blindly?

 

Really Really need to get my PC back up again :-(