Removing thermostat valve is not recommended. It is only useful during extreme summers, when old small cars like Mehran and FX start over heating due to aged radiators plus other factors. Kindly note that the thermostat valve should ONLY be removed as a last resort i.e. When you have tried out everything that could have prevented over-heating of an Engine during summers.
The Valve should be properly greased and placed in a safe place. It should be immediately re-fitted into the car just before winter starts. Before that, you can check whether its functioning or not by putting it in heated water.