[Q] How to update SGH-I747M to 5.0? topic

I have a rooted SGH-I747M on 4.1.2 that can't accept OTA updates as a result of being rooted. Can anyone tell me if there's a way to update my phone to 5.0 stock without losing any data, and if so where I can find a guide? I've searched these forums and google but all the guides I come across are for third party softwares (CM, liquid smooth, etc.)

Thanks!:)