is it straight forward to fit or whats to look out for

We have covered it a little here if you try the search. If you are a little bit handy with tools then you should be ok but there is lots of potential to feck things up.

Make sure thay CYL1 is at TDC before removing the pump. Also do not open the driver's door with the pump removed - You'll get wet!!

Depending on the age of the engine depends on how easy it is to remove - There are two types of pipe arrangement.

Also if the car has a lot of miles on already it's worth buying a new cam follower.