It is possible to physically separate or combine them using simple tools such as multi-purpose pins and hammers. In fact, people who like watches can adjust the straps themselves at home.
One thing to keep in mind is that after fixing or detaching the link of the watch chain, you must secure it with Loctite (a type of adhesive) to ensure it remains securely attached. Sometimes watch screws come out and you end up having to visit a watch repair shop. At this time, if you are unlucky, the watch may fall to the floor and receive a serious shock, so it is a safer choice to go to a watch repair shop.
Chris
VIVER diagnostic team