Default [Q] Problems updating via OTA and/or ODIN

Currently running G900FXXU1ANE2 on an EE branded S5. (Previously rooted with towel root and supesu)

keep getting notifications to update firmware but when I do it via OTA it comes up updated failed connect to kies (on PC) the problem being, I don't own a PC so that's not an option

I've tried installing mobile odin via the play store so I can install it manually,but when I try to open it, mobile odin just force closes. I've tried unrooting and re-rooting to see if that fixes the odin problem but to no avail.

Any suggestions on how to update via OTA/Odin without a PC or any other solutions?

Thanks
Previous: SGSIII White unrooted CM10
iphone 5 16gb black
iphone 5 32gb white
SGSIII LTE Omnirom 4.4.4
New: Samsung Galaxt S5 Sparkling white
To the mind that is still, the whole universe surrenders.