Or download them again from somewhere ?
From the threads i've looked at, seems you download them in the correct file type onto an SD card and into the unit.
Has anybody got any expertise in this ? there's a few on google but their a bit dated
I'd built up quite a few on the TomTom, can't remember having any issues in doing it and may not be compatible
Please anyone with the know how, give us an idiots guide
Michael