2.) Add SD in nuvi
3.) Turn nuvi on and flash in pre boot
Here you have all that you need:
Spoiler: This extract on SD
Spoiler: With this flash in pre boot
This pack is created in this way that when you flash in preboot with rgn this will start command from SD and if all go OK you will have 14xx boot.bin on your unit.
Yes, correctdo I just add the microSD in the GPS but not switch it on until pre-boot in step 2?