You can contact most airlines and do what is called a "status match." Basically, you say that you have top status on some other airline and would like to switch

You can contact most airlines and do what is called a "status match." Basically, you say that you have top status on some other airline and would like to switch to United, would they match you? If you haven't done it before, they'll typically offer a challenge (we'll give you gold and if you fly X amount over Y period you get platinum).