@feifeibapu
Searching for basic info is in fact the best option, volumes of info in the Tuts: [Only registered and activated users can see links. ]. This one is particularly helpful for those starting out: [Only registered and activated users can see links. ]. There's lots more, but sometimes it's a bit hard to see the woods for the trees because there's just so much info. Have a look around but your easiest option is to put AU/NZ unlocked image [or just NZ] and the JCV file on a microSD leaving the NA EOM map on the unit.

Post again if you need specific help, but please look at the tuts first.
PS: Welcome to GPSPower. I see the guys over in Android section haven't bash you up too bad either, we try to be kind to new members .....