Change old Tech Reumer GoogleMaps in FlexiContent's GoogleMaps

Hi,
I've got a site made for quite a long time with FlexiContent. At that time, there was no GoogleMap field in FlexiContent, so I used Tech Reumer's GoogleMaps plugin with {mosmap address='...'} opening and closing tags. Now, this plugin has been withdrew from JED and I've got problems with it, plus it's not very secured to have a deprecated plugin on the website. So, I would like to use FlexiContent GoogleMaps field. But there are quite a lot of maps in this site (about 300)... Is there any way to change old GMaps field with new one without loosing all datas ? Ie to change field type without loosing all datas ?
Thanks.

sorry impossible because json format isn't good....
maybe you can do it with an import

Thanks Micker for your answer. Too bad But maybe this wouldn't be necessary, because just few minutes after this post, there was an update of the plugin, the first in more than one year. Maybe a hope of rebirth...

Et puisque c'est de saison, très bonne année 2017 à toi, à la communauté Flexi et à toute l'équipe de C3E !

Merci, par contre je te recommande migré vers le champ de flexi pour 2 choses :
- la compatibilité avec le module flexi google map (permet d'affiché tout les points d'une carte)
- l'ajout futur de la recherche radius pour les champs de type google map (surement milieu d'année)
Vili

Merci pour le conseil. Je le ferai à l'occasion ... si on me donne le budget pour