Help how do I downgrade my phone?

[hello123345]

hello, I have an alcaltel one touch idol 2s And I recently made the upgrade the system wanted me to do but since then my battery drains like super fast, how do y un do the upgrade? apart from draining my battery it didn't change anything on my phone. it's the 4.4.2 upgrade

 

[glc]

Enter recovery and clear the cache partition.
If that does not solve the problem you may have to
backup your apps and data and do a factory reset.