one end of space bar not working

I don't know how this exact model is, but I can give some general advice. Most keys can be removed from the keyboard by gently prying them straight up. This is done by prying evenly from both sides using what iFixit calls a metal spudger (a non-pointy knife of sorts).

After the key pops off the mounting clips, be very careful, since there may be some small parts (such as a spring) that might pop out and get lost. This isn't too common, though. Also, be gentle, since some plastic bits can be damaged if you try to force them out by twisting.

A spacebar typically contains a "stabilizer wire" that goes from end to end, and its purpose is to pull one side of the key down as you push on the other side, making the whole bar go down evenly.

If your spacebar is wobbly, then probably this wire has either slipped out from its hold-down brackets, or it's become detached from its mounting clips.

You'll need to make sure the wire is correctly placed in 4 different places: the left & right side of the underside of the spacebar itself, and the left & right side of the area under the spacebar. In two of those places, the wire will clip in securely. In the other two places, the wire will slide under some brackets.

So first make sure the wire is clipped in where it is supposed to go, and then slowly put the spacebar back into place and make sure the wire engages the brackets, and finally push the spacebar straight down until it clicks into place (typically onto the key switch itself).

Actually, I'm peeking under my laptop's spacebar, and I can see two scissor-jack mechanisms under it in addition to the stabilizer wire. The scissor-jack is what is under every laptop key, and it is what the key top actually clicks on to. The scissor-jack is really a stabilizer mechanism in itself: it lets you press down on any corner of a key, and the scissor spreads that force to pull down the other 3 corners.