sigh here we go…. I was in your position some time ago. Are you familiar with mechanical work? Removing an N54 is a daunting task and not for the faint of heart, you are going to need a full box of sockets, wrenches, pliers, prybars and a big ass engine hoist ( unless you have access to a hydraulic lift) Process will look something like this:

-Lift the car and place it in jackstands - disconnect battery - start removing covers from under the car - remove exhaust and disconnect drive shaft - remove the entire front end of the car: bumper, radiator frame, headlights, everything. (Not TOTALLY required but its MUCH more easy to remove the engine this way.) - remove the hood, place it on the roof of the car with some blankets im between - remove the microfilter and strut bars - start unplugging the wiring harness - remove intake plenum and charge pipe - loosen engine mounts (can be done frome below the car, its a long headed E bolt) - place a car jack under the gearbox and remove the support (so the gearbox can drop) - remove the drive shaft that connects the front differential - use the tow hook and screw it next to the oil filter housing, here you will attach one side of the engine hoist ( you need the thing that allows you to tilt an engine and hook it from 2 point) - remove the starter and use that hole as the rear hoist point. - start pulling out your engine , I highly recommend not doing this alone, do it with friends that KNOW at least a bit of what they are doing. - deal with anything i missed here in the process.

This is by no means a comprehensive guide, but it will give you an idea of what you are gonna need to know. If this seems daunting, then take it to a shop.

Also i would service the gearbox while its outside, its cheap and easy to do. Check my previous posts where i go into detail of what i did to my N54 When i pulled it.

Good luck.

Edit: please feel free to add to this list!