A while ago my father gave me a watch but the length of its band is too long for my wrist.
Then I decided to adjust the band size at home after watching some YouTube tutorials. Firstly I bought this tool from Amazon for less than 2 pounds.
This tool has a screwable pin which easily pushed out pins from my watch band.
Now the remaining pieces are put back together by pushing in the pin with hand at first then helped by the tool.
After several tests, the watch band fits well by removal of 3 pieces.
Surely this is much cheaper than going to a watchmaker and I quite enjoyed the whole process.