Last night at CES, Nvidia and Asus announced that they will start rolling out the Android 4.0 Ice Cream Sandwich update for the Transformer Prime, the world’s first tablet with a quad-core Tegra 3 SoC, beginning from today.Quite a few users in the United States have already got the update and installed it on their Prime. Thankfully, some of them managed to preserve the OTA update file for other Prime owners to try. The sad part is that there is no clear way or a method with a 100% success rate via which Prime owners have successfully managed to update their tablet to Ice Cream Sandwich manually.

I am mentioning some of the methods below via which users might be able to manually update their Prime. Keep in mind that if a method fails for one Prime owner, it might work for you, since it all depends on the SKU of your tablet.

Method 1: First download this OTA Zip file. Extract its content on your PC and then copy them to your Prime’s SD card. Make sure you don’t copy-paste the files inside any folder on your sd card.

Re-start your Prime and it will automatically prompt you that a software update is available. If that does not happen, then go to System Updates under Settings and manually check for the update and then try.

Once your Prime successfully reboots after the update, go the System Updates and again check for a update. Chances are your Prime will prompt you that a new software update is available. This is the Ice Cream Sandwich update. Simply accept the prompt and then let it download and install ICS on your Prime.

Method 2: If you have root access, you can try downloading this ICS OTA zip file and then transfer it to your Prime’s /SDCARD/cache partition. Now manually check for a Software Update on your Prime and chances are it will prompt you that a new software update is available. If it does not, restart your Prime and then try checking again.

If none of the method above works, then sadly you are out of luck and need to wait until the Ice Cream Sandwich update hits your Prime.However, I will continue updating this post as I find more methods on how to manually update the Prime to Ice Cream Sandwich.