Replacing Ryobi PCN4545 oil pump?

Hi,

There are a lot of questions on here regarding the pcn4545 oil pump but none clearly explain how to get to it!

I have removed the clutch and can see the plastic worm thread that turns the oil pump, this isn't worn but it looks like the worm axle has slipped consequently it doesn't mate with the metal worm gear.

How, step by step, do I get to the oil pump? From the diagram I appears to be at the bottom of the engine underneath the crank.

I can't work out the order in which I need to remove things in order to get to the oil pump. Engine has to come out, but how?

Much appreciated

Thanks in advance

Jon