How to Upgrade from 3.1.2 to 3.2.0

[Timbow]

I had the first email yesterday from a customer saying that his admin was flagging an upgrade and what should he do and should I do it for him. I need to make sure I have a nice and simple, quick, safe method for upgrading because I don't want to create any problems, and other users will be looking in here seeking clear instructions. So what should they do to update an existing site? We have three methods: Which one is best?

First thing to explain is that nothing needs 're-installing', it's just a matter of updating files by ftp.

Always Backup First.

1. The wiki instructions are fine and should cause no problems
   
2. Shawn has suggested it might be simpler just to upload the whole thing over everything, but with a warning that if you have altered or deleted any files the changes will be undone.
   
3. I am going to upload just the 'admin' folder and index.php from the root.
   

The reason I like method 3 being that outside of the admin folder there are only five files altered. Two are very minor changes to themes which are probably not in use. One is to temp.gsconfig.php which is irrelevant to an existing site. One is to the anonymous_data plugin, also irrelevant to an existing site and the last is to index.php which should be updated.

Is that sensible? Or am I making needless complication out of a simple upgrade?