Installing official released Lion over Developer Preview 4

Many people have been having issues install the official release version of Lion on top of the Developer Previews. When going into the App Store to buy Lion it says its already installed.

The way around this is to hold [Option] and then click the Lion picture above the Installed. This will make the Installed text change to the price and then clicking this will make it say Buy.

For me this still caused problems, reporting that there was already a version on my HDD. However, I figured out that if you [Option] + click Buy also, it will allow you to purchase it.

It's just downloading so I don't know if it will install yet. Will keep you updated!!

UPDATE 1: Right now the download in LaunchPad just says "waiting".... wonder whats going on?!

UPDATE2: Eventually got Lion installed (I think!), but I'm not seeing some stuff and I read that this is the case with an upgrade from a Developer Preview. Going to install a fresh version. Will blog a how-to for reference and to help anyone else trying the very same...