A springbar is a clever device that attaches a watch strap to the watch.  Invisible when fitted, at the point at which the Mondaine strap attaches is a beautifully engineered and much ignored piece of ingenuity.
Mondaine Swiss Railway Watch Springbar
At the end of the bar one can make out two small rings. The first ring is the one which nestles against the holding lug on the watch stanchion into which the end of the pin to rests.  Next to that ring is a second one.  These two ends meet in the middle of the springbar where, not surprisingly, a spring holds the two in place.

Removing the Swiss Railway watch strap and manipulating the bar is the difficult bit.  We normally suggest that the Mondaine strap is cut off at the springbar with a very sharp knife or "Stanley" blade.  The strap can then be pulled away from the springbar and removed with the help of either a pair of pliers, or a small flat bladed screwdriver to compress the spring and remove the bar.  I hear you say "that's a bit terminal for the strap", which it is, but it is a cheap and cheerful, easy way to remove the strap.

Mondaine watch straps can come in various colours and it is a pity not to change them with your mood or your clothes.  The red strap in particular contrasts very well with jeans or casual wear, but also looks the business for more formal occasions.  This is where the springbar removal tool comes in handy, removing the Mondaine strap without damaging it.

Mondaine Swiss Railway Watch Springbar Removal Tool

You will notice that at the business end of the tool is a flat blade with a "V" cut out of the end of it.  This is inserted into the gap between your Swiss Railway Watch and the Mondaine strap.  Gently manipulate the tool to make sure you are directly over the springbar and that it is nestling in the crux of the "V".  Try to locate the gap between the two rings so that you can move the tool towards the other stanchion thus compressing the spring.  When you think you have caught the ring, and have successfully compressed it, move the tool away from your Mondaine watch and this should release the Swiss Railway strap.

We have created a video, please watch closely