You will need to take the maf off the car, simply unplug it, then undo the big jubille type clip on one side, and the two spring clamp bits holding it to the airbox on the other side.
Now look into it you will see two wires strung across support posts, 1 will be clean the other will no doubt be caked in grot, so spray liberally, DON'T under any circumstances be tempted to prod the wires(called hot wires), as they are fragile to physical attack!!
You will immediately see the cleaning effect of the carb cleaner on the hot wires, give it a good spray until spotless, shake the maf to get rid of excess cleaner, then put back on car etc.
Let me know how you get on.
tabetha