a single 1GB stick will work just as well, so if that option is a little cheaper you can go that route as well.
they are really easy to fit, firstly look at the row of connectors on the ram and you'll see an off centre slot cut into it, look at the socket and you'll see a little raised bit in the socket that matches the slot on the RAM, make sure you have the RAM the correct way round so the slot and and raised bit line up, then simply spread the two retaining clips either end apart and push the new RAM straight down into the slot, you need to push fairly hard, when the ram is in place the retaining clips will automatically click inwards to hold the RAM in place.
The slot and the retaining clips are pointed out by the arrows in this pic
http://www.dancetech....400_build_fit_ram.jpg