If you are from Denmark, log in to stardoll, click HERE and save the doll to your album. The necklace should be in your suite.
If you are from anywhere else, you'll have to use a manual proxy (How? Click HERE).
Web proxies don't work with this kind of contests.

These ones worked for me:
IP: 217.74.216.179    Port: 8080
IP: 217.74.216.178    Port: 8080
OR click HERE for more.

After setting the manual proxy, go to this link:

http://www.stardoll.com/en/contest/view.php?id=2175

Hit Enter and log in to your account. Once you log in, dress up the doll and save it in your album. You can now get rid of the manual proxy. The necklace should be in your suite.

ATTENTION: Even though these are not web proxies with ads, we can not ensure that you will be safe. I've been using manual proxies for some time and nothing ever happened to my account. These proxies are third party proxies, open for public use.

-MKA-RC-lover :)