Damn thank you ! So used to treat .img as .iso I didn't realize it was so easy

Maybe a last dumb question, but if I want to use my 2GB internal GPS memory (Garmin 250 Nuvi), I have to remove the old map. Biggest file is gmapprom.img, I assume I just have to remove it and than copy the GMAPSUPP.IMG ? Don't want to "brick" my GPS (didn't even know if it's possible), and I always do backup before...

thanks a lot and Happy New Year folks !