Download And Install Latest AOSP Android Open Source Project Marshmallow 6.0.1 Custom Rom For Sony Xperia Z3+ E6553. Before Starting I’m Clear one Thing Your Device boot Loader must be unlocked And Custom Twrp Recovery Installed. And Also you have working ADB & Fast-boot Connection in your Computer.
How To Install Android Marshmallow 6.0 AOSP Custom Rom For Xperia Z3+ E6553
-Copy Google Apps on your Device internal Storage
-Reboot Z3+ into TWRP Custom Recovery mode and make a Backup of your Current Running System (boot,system,data)
-In TWRP Recovery delete data & cache/dalvik
-Power Off your Phone and reboot into fast-boot mode
-Install the extracted system.img File “fast-boot install system.img”
-reboot again into TWRP Recovery mode and flash Google Apps
-Switch off your device and reboot into fast-boot mode
-Install the extracted boot.img “fast-boot flash boot.img”
-reboot your device (1st start take some extra minutes)
The File Name”userdata.img” in Rom zip just delete your internal Storage so please do not flash it.
Recovery: In the Rom Download is the “recovery .img” this is Sony AOSP recovery you can flash it but you can not do much with this & you do not need to install it.
If you really need to use TWRP, you can boot your Devices with TWRP “fast-boot boot twrpxxx.img”. You have to do this every-time if you need to use TWRP.