How to adjust metal wrist band on casio watch?

1. Pop out one spring pin to disconnect the band from the watch or from itself at the clasp. If you don't have a special tool for this, a needle or a pin will probably work. A straightened paper clip may be too thick, but they are cheap so you could try it. Now the watch and band can sit flat on the work table.
2. Examine the links. If some of them have little arrows on them (usually the ones closest to both sides of the clasp), they are removable.
3. These removable links are held together by a "U" shaped (actually a squared off "U" - sort of like this |_| ) pin that is inserted into the link. There may should be some kind of window-like opening in the link into which you can insert a narrow screwdriver or similar tool or even a small nail (around 6-penny size) and push out the |_| shaped pin. A straightened paper clip is probably not sturdy enough, but you could try it. Push in the direction of the arrow (from tail to point). The links that were joined by the |_| pin can now be separated.
   
4. Remove a second such pin from another adjacent link. Now a single link is free and can be discarded (or kept). Reconnect the remaining adjustable links with one of the |_| pins and re-attach the spring pin from step 1 so the band is reunited with itself or with the watch.
5. Try it on. If it is still too long, repeat the process. Good luck.
   

Http://www.watch-batteries.com/shortening_a_bracelet.htm

best of luck

Take it to walmart or any store with a jewelry section, they'll fix it