How to Flash:First of all backup all your important data.
Download the zip file from the given official link.
Unpack it on your Desktop.
Copy the Dload folder to your SD card root directory.
Make sure your phone battery is enough charge.
Now turn off your phone.
Insert SD card.
Press both volume keys "Up & Down" and then press power key until the software upgrade progress bar displays.
Wait until the progress bar finishes and the phone restart.
Check your phone firmware version in setting.
This firmware is officially released in july 2015, and its version is V100R001C328B101. Below is the link to download Y360-U61 firmware . Firmware download size is 765.50MB.