Those look to be an entire two sizes too big for you. I'd sell them and get them smaller, i'm not sure how the waist is snug on you when it looks like it's really loose.
You can shrink them again by hot soaking them in water for 30 minutes then putting them inside out in the dryer till they're completely dry, this will not change the color at all, it'll only shrink them down.
How much shrinkage could I expect in the waist and crotch were I to do that? Would it be drastic?