Here's a brief tutorial for those unsure as to how to change the strap on some Glycine models such as the Airman 17 and my D24 09 that use screw bars rather than the more common spring bar. I couldn't really find a good explanation online so thought I'd write one.
If you examine the watch you'll see what appear to be screws on the outside of both lugs:
It turns out only one side is actually a screw. The other is a screw head attached to a bar. Taken apart, they look like this:
By convention (I believe) the bar is inserted from the left and the screw on the right. At least that's the way it was on my watch. To take the bars apart requires the use of two screwdrivers simultaneously, one on each side.
The screw heads on D24 are 3mm wide. Try to find the closest fit you can, as too small a screwdriver can damage the slots. Also try to get the shortest driver you can as it's not that easy to hold in one hand while turning. One slip is all it takes to scratch the lug bar. (You may want to apply some protective tape the first time you try it.)
Finally be careful not to lose the screws--they fall out at the first opportunity.
Once the screws are out you can use a paperclip to push the bar out and then it's a simple matter to insert the new strap and re-tighten the screws.
It's much easier to do the second time, so don't rush and you'll be on your way to changing the strap as frequently as you desire.
Incidentally the screw bar dimensions for the D24 09 are:
length (with screw attached): 32mm
bar diameter: 1.8mm
screw head diameter: 3.0mm
I was able to purchase a second set for my watch from About Time in Dana Point. Thanks, Holly!