The first thing you need to know is how to upgrade your Android phone to a lower version.

Android cell phone system upgrade method:

One, OTA upgrade: to ensure that the phone network, enter the phone's Settings-About this machine-System Update, click to download the upgrade package to complete the upgrade operation, you can also find the system update icon through the phone's menu click on the direct upgrade;

Second, the local upgrade: the computer to download the upgrade package, copy the cell phone to the storage or the memory card, via

Three, PC suite upgrade: the computer to install the phone brand official PC suite or brush tool, data cable connected to the phone, select the downloaded upgrade package or directly download the upgrade package online through the computer to complete the upgrade.