as for cleaning out the sump I would personally just tip out what is in there, put in a cup of fuel and swish it about and drain it out again.
fuel tank and carb, tip out whatever is in there, and drop the float bowl off the carby, while the bowl is off make sure the jet (goes up the middle where the bowl nut goes) is free and clear, just be careful as you remove the air filter housing as the little gasket between the housing and the carby forms part of the primer and likes to tear.
The rope can be tricky to somone who hasnt doen one before, what you can do is, wind the spring so it has a fair bit of tension (4-5 turns, feed in the rope through the hole on the starter reel and using your third hand tie a knot in it and let the spring tension draw the starter rope in.
