Some times has left and as nobody was interested to give exact instructions, I took a time and made it clear for my self.
At Mobile XT I go working in folder garmin following file (map) names:
gmapbmap.img;
gmapprom.img;
gmapprom1.img;
gmapsup2.img;
gmapsupp.img.

At NUVI550 the good result is following:
internal memory
gmapprom.img
gmapbmap.img
gmapprom1.img
gmapsupp.img
gmaptz.img
gmapoem.img

MicroSD card
gmapsupp.img