Once you arrive at the funfair there are 2 UFO catchers, the middle and the right one which count towards this achievement. It really is very easy as there are only 4 items per compartment that you need to pick up and drop into the bin on the left. As with real life, the claw will sometimes drop them or you may miss the grab. I used up 20 coins getting this achievement. If you run out do the worm race for some quick coins.