Can i add that if you have a slender wrist the bracelet will make the watch look chunky. So if you have say a wrist size of 6.5" or less then I would suggest going the rubber strap.
You see the screw in the middle of the clasp in your 1st pic? well you unscrew that and then push out the bar that sits in the leather loop. That bar holds the middle part of the clasp in place. Just be careful with the small screw as it can get lost if you drop it.
Good luck!!!