Removing Jailbreak but Preserving Stock Data

[triple_illusion]

My apologies in advance if there is already a thread on this, but I did not find it.

I have a friend running an iPhone 5S iOS 7.1.2 and jailbroken using Pangu. He wants to remove the jailbreak entirely. He also has a delicate situation in that he has several voicemails from his recently passed away mom that he wants to preserve.

1. How do I completely remove the jailbreak?
2. Does that force his iPhone to update to iOS 8.x.x? or can it be be restored from a backup of his 7.1.2. version?
3. How do I preserve all of his voicemails?

 

[J. A.]

To completely remove the jailbreak, he should restore the iPhone using iTunes. His device will be updated to iOS 8.4, as that's the only software signed by Apple at the moment. It's possible to restore from the backup of his 7.1.2 version, but the software on the iDevice will be 8.4.

His voicemails are included in a backup. You can use iExplorer to save them, afaik.
It's also possible to use something like Audacity (software for the computer) to record them from the iPhone and save them to the computer. In this case, try saving the voicemails before restoring the iPhone, just to make sure they won't disappear, though.

Hope that helps.