Upgrade or Install Sony XPERIA M2 Aqua D2403 to Android Lollipop 5.1.1. The firmware 18.6.A.0.175 available for downloading https://drive.google.com/file/d/0B1AAC4lt7nzORWxJTHVSY1BPR3M/view?usp=sharing. You can download your Sony XPERIA M2 Aqua D2403 firmware 18.6.A.0.175 at the page. How to Upgrade Sony XPERIA M2 Aqua D2403 to Lollipop using Sony Xperia Flashtools: