620 Problems

Hi. I just got a new 620 for christmas from miggle.com. I want to know the most effective way to fix the crown in the middle. I have rods on the 50 and the two 15's, I don't know what I should do with those. I am not very good at fixing things so I would just like to know a quick fix, so that I can start playing. Thanks

P.S. Pictures would be nice