thanks for the input, I had to for go changing the gasket to the engine and only changed the cooler gasket.
The cooler gasket was bad and the engine to oil housing looked good but I knwo that its only time before it fails. (but wanted to change both. )

I have a low torque impact I will try this next weekend. As its buckled up already.

To confirm which end to hit? Bolt head or end sticking out or both? I assume the bolt head as I dont want to peen the open ends of the bolt.

Also will pick up some spine sockets

thanks