Garmin Fenix 5X map update

Hello all and sorry for my ignorance on the subject. 

    Recently i tried to update my garmin fenix 5x via garmin express app, having some map updates needed to be installed on my watch. The problem i encounter is, that the internal space of the watch is not sufficient for the update to be installed. Is there any way  to free up space on my device, other than deleting the fitness files, since i already tried it? 

   I have never encountered this kind of problem with previous updates, since every map update was easily downloaded and installed through express. My guess is that i need to erase the maps i do not need, p.e. Canada and USA, since i am located in Europe. How can i recognize which map is which? 

Thank you in advance. 

Kyriakos.