Fitting a Watch Strap that requires you to remove the spring bars, you can use a blade or a tool that has a fork like shap.Exmaple, Watch Strap that's code ends with the letter (G) requires gluing this can be a easy option then to remove and insert a watch spring bar, just cut the old strap off then .
Tool for removing a spring bar
The shape of the tool is a grove
Take the measurements between the shoulders of your watch where your strap goes this to will give you the correct size of Strap and spring bar you require, So if the width measurement is 18mm then you will need a 18mm Strap or spring bar.
The shape of the tool is a round bar, by pushing the spring bar out in this type of watch
Insert the grove in between the strap and the case of the watch then pull down releasing the spring bar.
Insert a blade in between the strap and the watch case pulling the blade down releasing the spring bar.
Hold the watch case then insert the lower spring bar into the spring bar hole then holding the watch and strap firmly push down on the top of the spring bar inserting it into the top hole.
Cut off the hold watch strap.
Thread the new watch strap through the watch case and the spring bar.
Apply glue to both parts of the watch strap and leave for a while.
Thread the steel clips the the other side of the watch strap.