[~The Jester~]

Backwards to how you got it out. There should be a small lip on the tube, that'll be flush up against the block when it's installed. I've always taken either an open end wrench (tough to do in the car with exhaust on it) or a flathead screwdriver like you did, and just tap her on in there. I little "Indian Head" or similar will make sure she seals up good for you.