I'm getting the message that my database have problems when I open outlok.

I tryed "rebuild" option but it not work.

Searched around some info, but no one match's my situation. I want to follow THIS steps, but I can't because the data takes 10Gb and there's only 1,8Gb free.
One obvious think is to make some free space on the drive, but another, an preferable way is to use an external drive to make the steps. 

As i can't find information about this way, i'm asking if any one knows how can i try to follow the steps using an external drive.

Another question i make to my self is: "duplicate" option does same than copying the "Microsoft 2011 Identities" folder and pasting it in the external drive as a backup method for the step 3.