How to go from win 8 OEM to 8.1

Disclaimers:

• Mods, if I this thread would be better in another sub forum could you please shift this for me.
• I am technically competent but lack match practice here. I am a former TechNet member and all I ever did to upgrade was nuke and install. I'm a believer in clean installs.

I have a neighbour who is seeking assistance from me to move her ASUS laptop Win 8 OEM (version unknown yet) to Win 8.1. This is a single purpose machine. She does her Family History research on it. I don't know yet if she does backups. I had a quick look last night and it seems to have a load of crapware on it.

If it was my machine I would manage it by nuking it and install Win 8.1 with update. I have the code as I was still a TechNet member until May 2014. I have full retail 7sp1, 8, 8.1, 8.1 with update, and the 8.1 update, all in x64 and x86 flavours.

The advice I am after is an outline of the way forward without having to pay for another licence. No need to talk about backups. I will just make it a condition of my (free) assistance that she has a suitable backup before starting.

thanks
Bob

Hello Bob,

She should be able to update to Windows 8.1 Update for free using Option One in the tutorial below.

http://www.eightforums.com/tutorials/32995-windows-8-1-update-windows-8-a.html

Update from the Microsoft store. Simple, piece of cake. Totally free.

Thanks guys, I will get back when it's done. It may take a few days.
Bob