WOW! :blink:
I've owned several Banshees and have no clue how to tell you to do this. I guess my best answer would be to look at it, contemplate, and come up with a plan of action and implement it. Past that I can't help you. I've never owned a Banshee that was oil injected. Not being a smart ass (well, maybe a little) but damn! I little investigation and I bet you can figure it out!
Maybe a little less general question would generate a better suited response.
SP