If the rod bearing is spun, you will need to replace the bearing, AND RESURFACE that journal of the crankshaft. Just replacing the bearing will not result in a durable repair, as the lack of a smooth and round journal on the crank will trash the new bearing in short order.
Back years ago, there used to be guys who could resurface a crank IN THE VEHICLE, but I don't know if that practice is still done.
If not, the only solution is to remove the crank, and take it to a machine shop for refinishing, and use new bearings as necessary.