[Q] How do i go back to O5Q? topic

So i am now at CM12, I need to go back to O5Q , When i tried to flash thru a zip i found it was stuck at booting!.
Researched a bit and found that i cannot do it like that i need to flash the fast-boot images of the other build.
But my question is , Is there anyway i can do it without losing My Pictures and Songs?
Last time i lost them and it was a big pain in ass!!
So my question any way i can get to stock without losing internal storage?
Thanks guy's....!