Taken and edited from XDA. link to original thread can be found at the bottom
Grab the installer image here:
http://nook.handhelds.ru/sdimage/generic-sdcard-v1.3.img.gz
it's a ~9M image that would unpack into ~130M disk image.
Write the image on your SD card. I tested with 2G, 4G and 8G cards and all worked.
Any uSD card of 1G or bigger in size should work if it is recognized by your nook.
Write on Windows by using WinImage and on Linux/MacOS X by using dd (to the entire device, not one of the partitions. The device name should not have any numbers at the end. The command is something like dd if=/somewhere/generic-sdcard.img of=/dev/sdX bs=1024k)
After done with writing, eject and then re-insert the uSD card into your computer.
Download a CM build from
here if you want to use a nightly or the newest RC(It is recommended to choose -87 nightly or later) or from
here if you want the latest stable version ( I would recommend this for you)
Put the file to the SD card (there is only one partition). Don't change the name of the file.
unmount the uSD card and insert it into the nook.
Boot from this SD card. It'll boot and will update you on progress.
When it's done, it'll power off.
That's it, you now have CM7 on your SD card.
How to install market and gapps:
After you have booted into the CM7 on SD card for the first time and set up wifi access (important!)
Go to
Latest Version - CyanogenMod Wiki and at the end there is a table with various google apps versions. Get the one suitable for your cyanogen version (CM7 is the latest for now). The file is named gapps-....zip
shutdown your nook and take the SD card out, insert it into your computer.
Copy the gapps-... file to the SD card on the first partition (titled boot) without changing the file name.
Insert the uSD card back into the NOOK and boot into "Recovery mode" by booting normally into Android, then from desktop hold power key until a poweroff menu appears, In the poweroff menu choose "reboot", in the next menu choose "recovery" and press "OK". The nook would reboot straight into recovery.
How to update to a new build:
put the new build you want to try on the first partition. (the name must be update-cm-*.zip or cm_encore_full*.zip or just update-*.zip)
Boot from the SDcard in the recovery mode (see above) and the new snapshot would be installed.
The partition layout would be preserved, filesystems are NOT reformatted, so your data should be safe.
If you get stuck you can read over the original thread
here