According to a Demi fanclub member (iluvmusic) on the fanclub:
It may sound confusing, but it’s easy. There was a presale last week but just for 3 shows. There is another round of presales starting on Wednesday at 12:00 local time. (You can check which shows are up for that presale on the “News Section” under the “05.13.10 – More Demi Presales!” article) You don’t need a presale code to enter the presale site, but to enter the presale site you need to click on a link that is under that More Presales article. If you enter it from someone who has posted it in a comment, you may get a message saying you need to log in to get your tickets. Even if access the link from the More Presales article way before the presale date, you may get that message; I think it gives you that message because it isn’t time for the presale. You can only access it from that article for security purposes.
Once it is the day of the presale, you may want to check a few minutes before 12:00 local time to see if the presale site is working. If it still gives you the error message, you can call the number that is listed in that message. Someone said that they kept on logging in and out of the fanclub till the presale site worked. It should work though.
Once inside the site, it will list the different shows, and I think a Buy Tickets option. I never got last weeks tickets, so I don’t know what other things are involved after clicking on that Buy Tickets. But I’m thinking it will be pretty easy to get them.
JOIN DEMI LOVATO’S FAN CLUB AND GET MORE INFORMATION!