Hi there need to find
You can find a lot of pictures and videos on how to do basic maintenance on your BMW at places like UTube, Pelican Parts, and Doug's Domain.
You did not mention the year and model of your car, but the general instructions for MOST BMWs sold in the past 20 years are as follows:
Pry off the little plastic caps and unscrew the 10 mm bolts that hold the plastic covers on top of the engine.
Most BMWs have coils over the spark plugs. You have to release the locks on the plugs and unplug the coils from the wiring harness. Then remove the two 10 mm bolts that hold on each coil. Tug hard to pull the coil out of the hole.
If your car has thick wires running to each spark plug (e.g. older 318 model), you don't have coils over the plugs. Grip the rubber boot, not the wire, when pulling the wire free from the spark plug.
Then you need a deep well 5/8" socket that is magnetic or has a rubber gripper inside to hold the spark plugs so you can pull them up out of the hole when they are unscrewed. You will need an extension for the socket to reach down in the hole. A 6" extension is enough.
The spark plugs for a BMW should have nickel plated threads so they don't require antiseize compound, but even with nickel, some folks put a dab of antiseize compound on the threads to make sure the plug does not seize to the aluminum head.
The plugs are made of porcelain (glass) so be careful not to drop them. A plug that has been dropped on a hard surface should be discarded, even if it looks OK.
The most important part of this job is to carefully start the plugs back into their holes holding the socket extension in your hand, not the ratchet. They should thread in easily. DON'T force them! If you cross-thread a plug in its hole, this simple maintenance job can turn into several thousand dollars in repairs.
If you don't have a torque wrench (and I assume you don't), you want to tighten the plug by hand until the copper gasket touches the head. Then take the socket and give it another revolution or so against some resistance as the copper gasket crushes. When the copper gasket is crushed, The resistance to turning will suddenly increase. That is when you stop turning. Remember that the head is soft aluminum. It has to be tight enough to seal tightly and not vibrate loose, but not so tight that it strips the threads out of the hole. ($$$$)
After tightening the plug, you may find the the extension pulls out of the socket easier than the socket pulls free of the plug. You can tape the socket to the extension, or use some other tool to reach down in the hole and fish the socket out if the hole.
