Upgrade Android 4.4.2 To 9.0 ((top))

Every manufacturer is different.

This is the first requirement but will void your warranty and likely wipe your data. Install a Custom Recovery: Tools like TWRP (Team Win Recovery Project) allow you to "flash" new software. Find a Compatible ROM: Search forums like XDA Developers upgrade android 4.4.2 to 9.0

: This usually voids warranties and can "brick" your phone if done incorrectly. Why It's Difficult Unsupported Software Every manufacturer is different