Summarize the following:
Download the file shown there (N7-720p_camera_mod-tl-aosp.zip). Switch off your tablet. To boot this way, simply press the volume down, the volume up, and the power keys until Fastboot Mode boots. Select Recovery. Click Backup and Restore, then tap on Backup. Tap on Install ZIP from SD Card, then select ZIP from the SD Card. Tap Yes. That's it! You're done.
Go to http://d-h.st/8Cw. Copy and paste the ZIP file to your tablet's SD card. Boot your tablet using Fastboot Mode. Boot into ClockworkMod Recovery. Make a backup (NANDroid) of your current ROM. Tap on the MOD file in the ZIP folder. Tap on Go Back then Reboot System Now.