Help!!!!!

So my catalytic converter literally exploded on me. I have all the replacement parts and am working on it now. I have 4 of the five bolts off but cant get to the one behind the altanator. I need to slide the alt over to get behind it but can’t seem to fine the bolts to undo it. It’s a 1.8 k series. Please help it’s driving me mad.
This little 10mil bolt seems to be rounded so I can’t remove the top bracket!!! It’s a tight area was thinking of getting the dremel on it and cutting it out. Any suggestions or instructions are fully welcome.
Thanks

Removing that 10 mm bolt, or even loosen it so alternator will pull away, giving access to manifold bolt