Fix it if you can get the parts.

The sleeve is usually stuck and you have to heat the block up a little to push the sleeve up with a wooden stick.

With the sleeve up and out, you can remove the piston/rod from the crank.

Remove the prop drive washer.

Push out the crankshaft.

Buy new bearings. Forget the old ones.

Get back on here with any problems.

The rod goes onto the crankshaft in a certain direction.

The cylinder sleeve has a definite orientation but you can determine this by aligning the higher exhaust port with the exhaust stack.

You can get the bearings from RC-Bearings.com http://www.rc-bearings.com/