1992 leaking oil from distributor shaft

My wife's car is leaking oil from where the distributor shaft would be. It is an electronic ignition so there isn't a distributor shaft, but the hole has a seal on it and I have to replace it. Does anyone know where it is located?

Is this a common problem and is it easily rectified?
I want to do it myself, I just need to know where it is located so I know where to start pulling stuff off. All this for a $2.00 O-ring, LOL.

Thanks for any help that can be provided

pull the air intake tube off, and look at the center of the back of the block on the drivers side. you will see a silver dollar sized stub shaft held down by a bolt and clamp. This is your oil pump drive. you will have to remove the throttle body for clearance, but it comes off easy and the gasket is only $3-$4. I would also put a small block chevy paper distributor gasket between the top of the block and the shaft for added insurance. Your Fel-pro part numbers are 70800 for the o-ring, and 70194 for the SB chevy paper gasket.