Best upgrade path to 10586 from 8.1GDR1 (Lumia 1520) while keeping app data intact?

[Persheis]

I've decided to go all out on the 1520 and try out 10586, yet I'm afraid I haven't ever enrolled in the Insider's Preview and have little to no idea on how to keep my info safe.
I'm mostly worried about mytube! videos saved on the phone (inside the app itself, not the ones automatically exported to the storage), but I'm interested in retaining all the settings, apps, contacts and messages while getting the best possible W10M experience.

What would the correct upgrade path for this particular requiremente be? I mean, should I backup 8.1 first, upgrade, hard reset, and then restore the original backup? Or upgrade, backup 10, hard reset and restore the W10 backup?

Kudos to you all!

 

[Mark Kaplan]

Always make sure you do a backup before you upgrade. Once you upgrade, you will be given the option to restore. Are you not storing your video's in the cloud? If not, you could also connect the phone to a PC and download all your files.

 

[Maurizio Troso]

I've decided to go all out on the 1520 and try out 10586, yet I'm afraid I haven't ever enrolled in the Insider's Preview and have little to no idea on how to keep my info safe.
I'm mostly worried about mytube! videos saved on the phone (inside the app itself, not the ones automatically exported to the storage), but I'm interested in retaining all the settings, apps, contacts and messages while getting the best possible W10M experience.

What would the correct upgrade path for this particular requiremente be? I mean, should I backup 8.1 first, upgrade, hard reset, and then restore the original backup? Or upgrade, backup 10, hard reset and restore the W10 backup?

Kudos to you all!

There's already a thread about that First of all, make a cloud backup trough settings, then enjoy