Procedure for removal/cleaning Champion R484SP carb?

I have a Champion (aka castel/lawn-king/trenchex) R484SP which ran absolutely perfectly until I let it run out of fuel (and then in the shed for 5 months) and it now runs very rough and then only on full-choke. Even then it will cut-out very often and as a result my right forearm is bigger than the left one from all the restarts! After reading many pages of advice on here, I've come to the conclusion that my carb is most likely blocked/dirty and it needs cleaning. Thing is, I work in I.T. and have no idea how to dismantle a carburettor. All I can see when I look at it is loads of weird springs and levers which I'm finding a tad intimidating. But, I am pretty good at fixing stuff and I reckon with some help can sort this out. Can anyone offer some advice on how to remove and clean the carburettor on this mower? Many thanks.