How hard is it to replace rod bearings?

I actually located a stock M20b27 which is 1.5 hrs from my house. The whole motor in running condition for $250. Includes Motor, harness, ECU, and a chip that Ive been wanting. This should make it much easier. If anything, Ill take the old motor appart and try my hand and refreshing the bottom end. Worst case is I waste $100 on parts and fuck it up. Otherwise Id say that its a pretty cheap learning experience.