how to install custom rom in xperia z ultra? I have recently rooted my Xperia z ultra. and now i want to install custom ROM in it. I have searched internet. but i am not able to find any safe way to install custom rom. how can i do that?
Follow these steps for installing custom rom : 

1.Unlock bootloader from sony official website instructions.

2.Install custom recovery like TWRP or CWM recovery to ease your further process.

3.Download custom rom like LineageOS or Resurrection remix whichever you feel good.

4.Boot to your recovery , wipe System data and install custom rom with Gapps.

5.Reboot and enjoy.