if your engine wasn't designed with one, you have to interrupt the outgoing oil flow from the pump, insert an oil filter appliance into that flow and restore the flow back to the engine. There are different ways to do this. Since I use an electric fuel pump and since I didn't want to drill the block, I ran the lines from the pump to the appliance and back to the engine distribution network out through the old mechanical fuel pump location. I've never seen anyone else do this, but it has worked excellently. I posted images of this previously. Others have drilled and tapped into their block and there are instructions on how they did that here and elsewhere. But essentially the flow of oil must go through the filter before it goes to the engine. How you do it is up to you.
