First we need to download lastest eMMC image and dump it to our micro SD card:

$ wget --no-check-certificate https://s3.amazonaws.com/beagle-debian/BBB-eMMC-flasher-debian-7.4-2014-03-04-2gb.img.xz
$ unxz BBB-eMMC-flasher-debian-7.4-2014-03-04-2gb.img.xz
$ md5sum BBB-eMMC-flasher-debian-7.4-2014-03-04-2gb.img
  6c8fe30763170969db97a31200a72828  BBB-eMMC-flasher-debian-7.4-2014-03-04-2gb.img
$ sudo dd bs=1M if=BBB-eMMC-flasher-debian-7.4-2014-03-04-2gb.img of=/dev/disk2

If we want to know process status of dd:

$ sudo kill -INFO <dd pid>

Afterwards, while holding down the USER BOOT button (the one next to the micro SD cad slot), plug in the power cord for the BBB and release it when all 4 LEDs are lit.

Wait for 30min (more or less) until all four LEDs are lit again and not blinking!

Default username/password:

* debian/temppwd
* root/root

If everything fails and we can boot from SD card you can write manually the eMMC by running this script in your BBB:

$ /opt/scripts/tools/beaglebone-black-eMMC-flasher.sh

Upgrading to a 3.14 kernel is easy as following these steps:

$ wget --no-check-certificate https://rcn-ee.net/deb/wheezy-armhf/v3.14.0-rc8-bone0/install-me.sh
$ chmod +x install-me.sh
$ ./install-me.sh
$ reboot
$ uname -a
Linux beaglebone 3.14.0-rc8-bone0 #1 SMP Sat Mar 29 00:25:15 UTC 2014 armv7l GNU/Linux