Help! How to downgrade?!

I have several RBP2 running 14.2

Unfortunately one of them upgraded to 15 as I accidentally click YES to upgrade.

As my current skin, and custom addons are not compatible, I need to downgrade to 14.2!

Is there a simple way to do this from ssh?

Many thanks.

If you use several RBP2 with similar configuration you could just clone the SD card from one of them and adjust your settings after that.