You can't, Navman maps can'T be cloned, copied or modified for the use on other devices.
Howeer, you can have a look at
[Please Register or Login to download file] and there it says your device can not be unlocked for other software because it is not based on WinCE.
It seems you are stuck and need a new map from Navman or a new device altogether.
Sorry for the bad news.