With great difficulty. OK, all joking aside, it is not as easy as it sounds. What functions as a PCV valve on these BMWs is under the intake. If you plan on replacing this, make sure to get all of the associated hoses and pipes. If they are not already cracked/soggy/dried or otherwise unusable, they will be by the time you get them off. It may not be a bad idea to check for oil leaks coming from the oil filter stand gasket. Those are a common leak point, and if you remove the oil filter stand, it makes the job much easier. If you don't have small hands, hire someone who does. At my shop, that's me, so I always get stuck doing this job every time one of these comes in.