How to make Opera Mini the default browser?

I have tried many times to change my phone browser from the stock android to Opera mini... As you all know the stock browser is slow and unresponsive. Before I get overloaded with comment: YES I HAVE CLEARED THE DEFAULT FOR THE STOCK BROWSER THEN TRIED CLICKING ON A LINK. And: NO it has not asked me what browser I want to use. IT just opens in stock. I then tried installing Firefox. I did the whole process again. I went to open a link and hit "open in browser" and what do you know, it opened up in firefox! This was great to see. Unfortunately I can't get this to work for opera. Although firefox mobile is great I have a preference towards opera. If anyone knows of a solution to this I would apreciate it greatly.