Root [Sprint] Please help walk me through going back to stock

[Thatdad]

As of right now I am running cm11 m12. I got my phone number changed and can't activate.

Well turns out I made a cwm nandroid backup rather than twrp (noob oops)

So basically I need to flash stock and update prl etc then go back to cyanogenmod.

I have Ubuntu so I can only use heimdall. Can anyone tell me or link me a video explaining the process?

 

[rlphbgby]

Here

For a video here