How to uninstall new android update?
In such a short time, that is not very surprising. Much of the membership is in the North American continent, which at the moment, sleepeth, or is only yet bestirring itself.
I've merged your two threads, and recommend joining as a member, which will allow you to give more details about device type, carrier, and update. Here's how:
As for the question.
It's not so easy. Android is not like Windows where you have a list of installed updates that you can remove. Once an Android system update is installed it's done. Even if you factory reset the phone, it only wipes the user data and reverts to "factory" settings for the NEW version that's installed.
Depending on your phone, you MAY be able to revert to a previous version if the manufacturer has made the images and tools available. This WILL result in a wipe of the device. However, you will get prompted for the update again.
If you need additional help or have more questions or details to share, please join the site so you can reply in this thread. See this link for instructions on how to join Android Central.