Delete unwanted, pre-installed apps.

[Klaxonn]

Hi,

As the subject indicates I am looking to delete some of the pre-installed applications on my Z3. I have had the phone for a while however, the frequency of the updates, the way in which Sony has pre-determined which apps I want to use is now very irritating.
I have my own apps installed, ones I trust and know and would like to remove, permanently, those I deem unrequired. Is there a way of deleting these applications, which currently are locked or am I forced into rooting the phone first, thereby probably invalidating the warranty.

[MatsSoder]

My phone is infected with adware and junk that makes it more or less useless. It does not seem to be possible to remove theese as they claim to be "important system applications".

Reset to factory settings does not help as they came with the factory firmware.

Does anyone know of a way to remove "important system applications" or a way to root a Z3 with Android 5.1.1?

Regards

Mats

[Uliwooly]

@MatsSoder

Check the suggestions on this thread and also could you elaborate on adware and junk? 

[MatsSoder]

I tried to "disable" the apps that i can not uninstall. They however restart automaticaly again.

Adware and junk are all the applications that i do not use, and have no other purpose than trying to promote something or trying to make me give away my personal data. Apps such as "Whats new", "Ar effect", "Lifelog", "Music" and so on.

Theese apps are a huge security risk and it is very irritating when an app i never used starts to make noise at 4am just to let me know that Sony have released some music from a group i never heard of....

[Uliwooly]

@MatsSoder

Do you have a taskiller, clean master, etc? bc once you disable them, they should not be enable