It's unheard of for a rod bearing to fail absent major abuse. You need to do a lot more diagnostic work before concluding this is the problem.

You didn't say what the problem was. If the engine has a rod knocking, you cannot fix that with a new rod bearing. Once a rod knocks, the impact loading on the connecting rod stretches the big end opening, and a new rod bearing won't fix it. The engine will still have a rod knock. It takes a resized connecting rod and a new bearing to fix that.
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john

I'm not sure. I first thought it might be a stuck valve and I put some Seafoam in the gas and in the oil to try to free the valve, but it knocks and at an idle the oil light flickers, which I figured might be due to the thinner oil with the seafoam.
Jimo

I'm sure that it can be done in theory, but if you have a bad rod bearing you might have bigger issues to deal with.

Without having done it on a V90, the typical steps are:
Remove the oil pan
Turn the crank so the bad journal is down
Remove the rod bolts and cap
Push the piston up a little
Replace the bearings
Check the clearance
Oil the new bearing
Reassemble and refill oil

It would be an enormous pain in the butt to do this laying on your back in your driveway.

Greg