[Alteration Q] Help with an alteration Sewing Machines Parts and Sales in Los Angeles

http://imgur.com/a/4gpJF

I was wondering if someone could advise me on making an alteration to this dress. What I want to do is turn it into a skirt and I it looks like it may be trick because of how far down the zipper goes? I’m still fairly new at sewing and I’m not sure if I should try it myself or maybe just ask a tailor to do it for me? Thanks.