If you like the look of it, or removing your popcorn ceiling isn't an option, then painting over it is your best bet. It's not that difficult of a project but it can be a tricky situation if not approached correctly.
Using a flathead screwdriver, remove all of the switch and outlet covers from all of the walls that you want to work on. Once you've done this, cover the outlets and the switches with blue painter's tape.
It is important to note that this color is going to create the white part of the jean look. But beware! Whatever paint color you had underneath decades ago may rear its ugly head. To avoid this from happening you will want to prime the walls with a light yellow, white or cream base coat. You may even want to add a second coat if the old color is especially vibrant.
Remove the baseboards by prying them off with a putty knife. (In some cases, you can keep your existing baseboards, but it won't look as nice.) Remove your old baseboards gently, as not to damage the drywall. If the putty knife is not working, use a pry board instead.
Cover your furniture and floor with tarps. Don't forget your gloves and protective eyewear. Apply taping mud, also called joint compound. This is a substance you already have on your walls in a thinner and more even coat; it helps get rid of the seams between pieces of drywall.