SWATCH BUCKLE REPLACEMENT
Firstly You do not need specialist tools as none are supplied.
All you will need a pair of long nose pliers.
Place the closed pliers inside the buckle as close to the centre buckle pin as possible.
Very gently open the the pliers, this will gently bend the buckle sides to release one side of the pin points,from the plastic buckle.(you only need to release one side).
Slide the strap and buckle peg off the buckle centre pin.
With the pliers pull the pin out of the other side out buckle.
Very carefully reverse the process to fit the new buckle, remembering to put the buckle peg in before you relocate the buckle pin.
PLEASE CHECK YOU BUCKLE FIRST AS SOME ARE FITTED WITH SPRUNG LOADED PINS, SIMULAR TO THOSE USED ON NON SWATCH WATCHES TO SECURE THE STRAP TO THE WATCH CASE.THESE ARE FOUND ON METAL BUCKLES MOSTLY.