Adding more butt coverage – bikini bottoms Sewing Machines Parts and Sales in Los Angeles

Hi. Complete sewing noob here. I have a pair of bikini bottoms that look great, but it doesn’t cover enough of my butt and wanted to get some advice on what would be the best route to take.
I was thinking the only way to add more coverage is either to just add more fabric or (something I found online) to do some seam alterations as explained in the link here under “Add More Leg Coverage”. Picture diagram. Any other routes I can take? Something I can do by myself or should I just go to a professional?