Hi Kenny, I had to do mine the other day, after a trip to the mud factory. Right, the actuator is the worst designed thing on a Landy. To take this out, you have to remove the link fron the cable.
Then there is a silly arangement of clips holding it on to the back plate. Have a good look how they go in, before removing them.
Once you have it out, then give it a good clean.
*BE CAREFUL HERE* there are two silly little rollers that go inside the actuator, and the tapers on the pins are what spreads the brakes..
Clean it all, and give it a light rub with emery cloth or suck like. I ended up putting mine back together with NO grease, as this only seems to attract the Poo.
Once cleaned, put back together in reverse order, and make sure the rollers are in the groove.
Squeeze it all together and put a bit of Masking tape round it to hold it together, whilst you assemble it. After the shoes are back in place, you can remover the tape.
Once this is done, then adjust your cable, so that it has a little play, and bobs your uncle, it SHOULD work.
Bit long, but i hope it helps.. :D