[Barnes & Noble Nook Tablet] digixmax:
[Caveat emptor: adopt/follow this guide at your own risk].

[

Important Note:

this process is applicable for CM11 builds that still maintains two separate partitions for /data and /media – as in CM10.x and stock ROMs (see http://xdaforums.com/showthread.php?p=48612997#post48612997 for more info). If/when these two partitions get merged in some future CM11 builds (as being contemplated by our NT CM developers – see http://xdaforums.com/showthread.php?t=2560827&page=28) this "CM10 to CM11" update process will

not

be valid for those future builds with merged /data+media partition].

Below is the process that can be used to update your NT EMMC from CM10.x to CM11.

Download the following files to a location in your user content-media storage space on the NT:

the flashable_CWM_6.0.4.5_chrmhoffmann.zip file from https://www.mediafire.com/folder/xjwc1a482a6ll/Nook_Tablet which contains the CWM recovery v0.2 provided by Chris Hoffmann (in the first post of the XDA Official CM11 thread http://xdaforums.com/showthread.php?t=2560827).

the zip file of CM11 ROM build of your choice from http://download.cyanogenmod.org/?device=acclaim (see http://www.cyanogenmod.org/blog/cm-11-m4-post-release-items for considerations in choosing nightlies vs. snapshot/stable builds)

the zip file of the Gapps package corresponding to CM11 – e.g., from http://wiki.cyanogenmod.org/w/Google_Apps

Boot into your current emmc recovery

Select install zip and install flashable CWM recovery zip file (obtained in step 1(a)).

Select reboot to boot into the new emmc recovery

(flashed in the preceding step).

Select Wipe data & factory reset.

Select install zip and install CM11 zip file.

Select install zip and install Gapps zip file.

Reboot into the new CM11.

Once the NT boots up, set up the wifi connectivity and your google account info. If you had previously enabled Google backup service on your CM10.x your Google Playstore apps will be auto-downloaded (but their settings will not be auto-restored).

If the NT on occasion boots or reboots into a black screen (in lieu of CM boot animation), then you have encountered one of the "random boot crashes" – more info and potential remedies, see http://xdaforums.com/showpost.php?p=48941796&postcount=94 and http://xdaforums.com/showthread.php?p=48301259#post48301259.

A few additional points worth noting:

Flashing CM11 requires CWM version 6.0.4.5 or later, or TWRP version 2.6.3.0 or later. To create a flashable recovery zip file for TWRP, use an archive file manager such as 7-zip to delete and replace the recovery.img inside the flashable recovery zip file (obtained in step 1(a) above) with your choice of TWRP

internal

recovery image file from http://techerrata.com/browse/twrp2/acclaim (e.g., openrecovery-twrp-2.6.3.1-acclaim.img). Remember to rename the downloaded TWRP .img file to recovery.img before inserting it into the recovery zip file, and also rename the resulting new recovery zip file to some other name like flashable_TWRP_2.x.y.z.zip to avoid future mix-up.

Installing CM11 ROM and Gapps will override your NT's CM10.x boot, recovery, ROM, and Apps, so make sure that you backup all this stuff using recovery backup function, for easy in reverting to CM10.x if desired. See my post at http://xdaforums.com/showthread.php?p=48612997#post48612997 for more "Info and Tips for Mitigating Risks in Rooting and Flashing Custom-ROM".

I would advise against using any other functions of the recovery without first carefully researching to understand what they really do.

My thanks to all the developers who collective work created the wonderful CM11 ROM for the NT as well as the tools and info I made use of to install it.