Choose which link you are going to remove. Use a thin pointed object (eg a compass) to push the pin that secures that particular link, following the direction of the printed arrows on the underside of the metal link.
You should be able to push the pin 2 or 3mm and then pull it out from the other side using a small pair of pliers or by hand. Place the pin on one side, you will need it to put the bracelet back together again.
Repeat the pin removal process on the next link's pin. When you have finished, you should have two pins ready to use later. Remove the link and put this in a safe place in case you need to re-fit it in the future. If you need to, remove another link on the other side of the clasp, using the same process, this will keep the bracelet even and help it sit correctly on your wrist. When you have removed as many links as you need to, you are ready to join the bracelet back together.
Reassemble the watch band. Once the required links have been removed the pin will need to replaced into the band to complete it again. To do this, replace the pin in the opposite direction to the arrows. If you need to, you can gently tap the pin back into place using a small hammer.