How do you set the camshaft timing on a BMW 3 series?

Good question. Well there is a few ways.I wont go too much in detail.I'm assuming you know a bit about cars. You can buy a tool for it which will run about 200 bucks. Or you can by a haynes book,and it will tell you how to make a template.First you got to get the number one piston at TDC.get you a breaker bar with i think it's a 22mm deep well socket. you will need a second eye for this job if it's your first time. take the number one spark plug out(first one from the timing chain). get a long enough screw driver that you can touch the piston with. turn the crank with the breaker bar,with your help watching the screw driver.Once the screw driver cant go up anymore that's it you are a TDC.A good way to know is you will hear air out the spark plug hole once it gets close to tdc,that's with any car. There is a square thing at the fire wall side of each cam shaft. They both have 2 dots on the same side,you will notice those dots will be facing up. really it would be about a 45 degree angle. And the outside sproket on the passeger side cam(exhaust) has a arrow that will set at a 45 as well. This is for camshaft removal and installation. Your cam tool or template from the haynes book will let you know for sure if it's in time. I don't know what step you are in,so i started from the tare down. BMW is the most fun to work on.