If you want to use the second method Master reset your Nuvi.
Rename Txt ,Voices and Keyboards folders in your Nuvi to another name eg Petx Poices etc.
Prepare .rgn from 34xx gupdate
Flash 34xx firmware with updater, following instructions in post one.
At this point your Nuvi will restart without logo but as a 34xx.
Download the file from Wupload or from the Turbobit mirror,unpack the file to an empty SD card, turn nuvi off, insert the card, turn nuvi on. Remove the sd containing files.
Those files will add the right 34xx logo and will enable some of the features.
If you want to add all the features download the attachment and unrar it, add these files in Garmin folder in your unit
Remember to reset it again and to go to MTP Settings and set it to Mass storage mode.