How can Iupdate CM11 to CM12 topic

Earlier today, I decided I wanted Lollipop on my One. I went to the Cyanogenmod website and used their installer.

I thought I was going to have lollipop but I ended up with CM11 4.4.

I then noticed a different recovery was flashed onto my phone by this installer where I cant seem to mount or unmount, backup, restore etc.

How do I go about getting to 12, the Nightly builds?

Thanks!!