How to root the HTC One Mini (m4) and make a backup of the ROM?

[cassail]

I want to root my HTC One Mini (m4) which was a contract phone with O2 (UK) - I now have a new phone, but I'd like to use the m4 to experiment with.

Before I start playing, I want to create a backup of the phone exactly how it is now. Nothing of any importance is stored on the phone so I'm more than happy to reset it if I need to. I just want an image of the phone so if anything happens or breaks, I know I can just use my backup to get the phone working again.

I have read of methods which involve rooting the phone before backing up and using recovery mode to create an image. But I'm concerned that I create an image from the rooted phone, I'll have a rooted image that I can't unroot and return the phone to exactly how I bought it.

The CID of the phone is O2_001 and it currently has a GiffGaff SIM card in it. As far as I know, GiffGaff use the O2 network - but I don't plan to change networks at this moment.

I hope I've covered what I need to in my very first post. I'd really appreciate some help to a complete newbie - hence all these questions which are probably surrounded in confusion by myself!

Thank you.

 

[cassail]

Bumping this so it hopefully attracts more attention. I'm not too happy about it being in the m7 forum, when even my thread title says my phone is an m4.