Tranny case bolts stuck

Hi all. Does anyone have an idea how i can undo these 2 bolts ?
There parshly rounded from the last owner and the allen key just slips.

 

blob of chemical metal on the end of another bolt put the end of that bolt into the heads where they have rounded and let it harden properly and then try loosening them?

When you put the cover back on use the conentional 8mm/10mm bolts much better than allen key ones im sure they sell them cheap on ebay

 

Thanks man and a really good idea.
I shall try that but if all fails i tey drill them out.

 

I may have to try that with the last one. I got one out so far while snapping a allen key at the same time and stabbing my hand haha