I would like to install the time-lapse application from Sony app-store and occasionally found that my firmware obsolete, so that would be a good time to update it also.
Here is my experience of update from 3.10 to 3.20.
First above some general recommendations which applies for firmware updates, please, read them carefully.
I am downloading required firmware from the following web site: Sony support.
Camera is ready for update! Let’s begin!
Note: Software provides very accurate instructions what to do during the update read them carefully, they might be different in your case.
10. Disconnect USB cable.
11. Do a hard reset (remove battery or external power source).
12. Check if version was update correctly.
P.S. This article represents personal experience and doesn’t replace official firmware update guidance from Sony. Author succeed in this procedure and can not be blamed for a break bodies. 🙂