1.connect your device to pc via USB
2.it will open as GARMIN mass storage on your pc
3.open GARMIN drive from my computer
4.if windows 7, look left side Organize->Folder and search option
5.click View Tab ->click show hidden files folders
6.uncheck hide protected operating system file.
8.open .system folder and delete gmapprom.img and paste your india map file and rename it to gmapprom.img
9.copy JCV and SID folder to GARMIN main folder as shown in the image.