Identify the removable links
Remember that all links in a watchband cannot be removed. Some of them which are adjacent to the watch clasp are permanent, which means you should not even try removing them. In order to identify the removable links, simply look for arrow marks at the side of the watchband. Links with such arrow marks are the ones which can be removed. Choose a link that you would like to remove and mark it with a temporary marker.
Remove the pins
There will be a couple of pins, keeping the links together. Remove those pins from their adjacent links. In order to perform this task, simply place the watch on a flat surface such that the links are in a vertical position. You should be able to see the arrow marks in this position. Now, with the tip of a pointed tool or a thumb tack, touch one pin on its head and apply a small amount of force in the direction marked by the arrow to slide out that pin. Use the same technique to remove the other pin as well.
Set the removed link aside
When you have successfully removed the pins, pick the detached link and set it aside. Do not waste the pins because you will need them to re-establish the connection between the remaining links.
Join the remaining links in watchband
Bring together the remaining links and insert the pin in the empty hole visible in the link. You simply have to reverse the process from step number two. Apply force with a pointed tool on the head of the pin until it is completely in level with the edge of the watchband.