First off, I take no blame for anything that happens due to this. This can potentially brick your phone. If this bricks your phone, makes it unstable, kills your cat.. YOUR FAULT not mine.
Please, don't make typos in the commands.
Eng Hboots allow you to flash unsigned images, and opens up more fastboot commands. Most people do not need this. This will not [provide perm root, or un-writeprotecte the emmc chip. In fact, if you don't have s-off it won't work for you.
radio (ship) s-off
Busybox properly installed
If you do not have busybox, you can use this app to install it https://market.android.com/details?id=stericson.busybox
Download the ENGHboot for Vivo here:
put the file on your sdcard
Follow these commands
busybox md5sum /sdcard/vivo_enghboot.img
dd if=/sdcard/vivo_enghboot.img of=/dev/block/mmcblk0p18 reboot bootloader
You should now see this, and are done.