Early last month, I have been informed that the HTC One M8 receive updates Android v5.0 Lollipop in early February next year. Now, Android Rom Lollipop for HTC One M8 is available for you to download.
Yup, thanks to smart people XDA Developers you can immediately try Android v5.0 Lollipop in the HTC One M8. But, if you've never done flasing Rom, rooting or anything like this, we recommend you not to try it. We are also not liable in the event of failure or damage when the installation is in the smartphone Android Lollipop One M8 you.
Well, if you've never done anything like this please you downloaded at the source link below, and follow all the instructions to uninstall it. You need to remember, Android Lollipop ROM is still under development and is definitely some features will not be able to work well.
Good luck .....
Source: XDA Developer