when you say conrod, you mean the thingy attaching the piston to the crank shaft right?
Take some pictures of the damage for all to see.
Maybe you just need a new connecting rod and all will be well.
Unless you have done damage to the piston and cylinder, dont bother replacing the rings. And if the crank case isnt cracked and leaking oil then its fine.
To get the crank case off, just keep at it, its only held on by a rubber oil seal, but it may be stuck, you can pry it of, or try to jiggle it, jsut apply a bit of force, dont be afraid of it. just dont damage the gasket if you want to reuse it.
