Just wing it. If you succeed, well done. If you don't, what the hell!

The sentence means 'I just have a try, although hopeless. Hard to say. Maybe I can get it.'

means a blind cat is trying to catch a dead mouse, it depends on the lucky only,but the result is not the most important. This sentence is commonly used to say someone tries to do something,but has no confidence and pays much attention to it, only depends on his lucky and God made.

It means a blind cat catching a dead mouse. If it manage to catch, good for the cat but if can't, too bad.