DIY: R53 Cylinder Head Installation

mITV @ cooperSml @ YouTube provides this video and warns:
Installing the head is a difficult job requires many steps including on the disassemble where you need to record the timing position that is going to be used when putting it together.

The space when installing the cam shaft and chain is very tight, the chain keeps getting into the sprocket and get stuck and you need to start again. it is important that the sprocket timing position with a paint that will not come out with oil or touching, because this will be one risk,