There is a root guide for 12b firmware. You have to flash back to the old firmware, root, use ota root keeper, ota update, then restore root. And the pro version of link2sd will link app+app data. I covered this in detail in a thread that got deleted. Idk why they deleted it, I'm just promoting the only app I found that worked. I tried the SD swap and the SD hack but I had issues and the developer was to busy to resolve them. I have 12b, rooted, with link2sd pro linking all my apps to SD second partition, and I converted some system apps to user apps, which broke the apps till I ran fix permission app to fix them. All of these apps are in the google play store. I'm in bed on my phone. If you need help still pm me and I will help you in more detail when I can get in front of my computer and use a keyboard that is better suited for my fat fingers. This is such a common issue I might post a new how to thread about how I managed to fix my out of memory issues on the f6, because I've tried every suggestion and this is the only one that works perfectly for me without any issues at all.
