And now its time to cut the track. I use a hacksaw to do the actual cutting. Here you can see that I've started to cut the base at the mark farthest from the end that I'll slide the base off.
Here you can see that I've cut through. Using a hacksaw means that you do cut the track a tiny bit so be careful.
Then pull the base off of the track.
Now cut the piece that you've removed and toss the cut out piece away, you need to keep the end piece.
Here's the removed piece cut. I'll toss the piece on the right and reuse the piece on the left.