How to I update my PRL/Profile and 4G on Sprint using a custom rom like Cyanogenmod and a Sprint MVNO like freedompop?

Generally the in the past the answer has been to have a backup of your OEM rom, and your current one. Then using your custom recovery restore the OEM rom for PRL updates.  Here is an alternative.

CM12 on Sprint, how can I update the prl? from cyanogenmod

http://forum.xda-developers.com/showpost.php?p=58118888&postcount=46

 

For 4G fix:
http://forum.xda-developers.com/showthread.php?t=2798619