There are two springs on an A1000 spacebar. You'll see a couple of raised dimples, about the diameter of the springs themselves on the base of the keyboard, to the left and right of the switch. On the underside of the space bar, you'll see a nipple of sorts and it'll become obvious to you how the thing snaps in place. It's easiest to get the retaining bar clipped in first, move the space bar out of the way, rest the springs on their dimples and then carefully lift the spacebar up onto and then over where it snaps into its switch in the centre. Takes a little bit of patience and some practice is all.
