May be I am one of the few with non-rooted phone. I was very close to perform rooting. All I want is to delete unused apps. There are some factory apps witch I don’t use. I disabled these apps. After a few weeks i had about 100MB of free space. Some apps require more than 100MB just for update.
I started to look in phone options. I saw button “uninstall updates”. I “uninstalled updated” on one disabled app. It free about 30MB of space. The strange thing is that, this app restored old version without internet. So … these “default” apps versions are saved somewhere. I removed updated of all disabled apps. At the end I had ~500MB of free space.
Rooting is rescheduled 🙂