Now we're assuming that you installed the v1.4a in NativeSD mode. Therefore, you access to the root of your SDCard (the window which is automatically open by Windows or Linux or MacOS or the FileExplorer in the ROM, etc...) and find a folder which is named NativeSD, you go in, find a folder which is named NexusHD2-JellyBean, and you rename this folder to NexusHD2-JellyBean412 (I just noticed I made a typo in my last answer ^^).
You can use a SDCard reader and put your SDCard on it and perform these action on your computer.
You can also use the provided by CM FileExplorer and rename by long pressing the folder in question with the name mentioned above.
If you installed the ROM to any other mode (fullNand or DataOnExt), you're not concerned (just in case you or I have misunderstood).
Thanks
I installer it NativeSD mode.
Now I will first wipe cache and Dalvik Cache instal zip from sd card and rename the folder.
Thanks for your help