320d valve cover gasket replacement

[Seany88]

Hopefully someone will be able to help me through this. I've had a burning oil smell through the heater system for a while now that disappears when the air-con system is on. I finally took it down to a garage and they reckon its the valve cover gasket because oil will seep out and drip onto the manifold so that when the normal heaters are on it takes air from the engine bay hence the smell (but not with air-con as its a closed system).

So, assuming this is true - anyone care to enlighten me on how to replace the gasket? I know its not a hard job on petrol engines, but diesels have high-pressure injectors etc so does it get a bit more complicated there? Anyone have a step-by-step guide or know where I can find one?

Thanks