Sit down with them and have a family meeting. Let them know that you have decided that now is a good time for you to transition from being their mommy to being their mom (or however you want to word it - keeping it light-hearted). Start with compliments of how proud you are of them that they are not dressing like sluts, sleeping around or doing drugs. This will let them see that you are not going to attack.
Ask them what they think is reasonable for them to do to contribute to the family chores. They will feel like they are being treated as adults. Even if they have a job outside of the house, they need to contribute to the cleaning, etc. After they have spoken, tell them what you agree with and what you would like to add. Be sure to tell them what were good ideas.
Then let them know that they can do their own laundry now and clean their bathroom and bedrooms. (Maybe this is already the case.) They will need to come up with a schedule that works for them on the bathroom they share. (Don't decide that for them.) If they complain that they shouldn't have to clean or that they don't want to as often as you'd like (or don't have time, etc.) then let them know that you will be available for pay. Remain calm, serious and very matter-of-fact. Let them know that they need to be prepared for the real world and that is how it is done. Lots of people can't or choose not to clean their homes and pay to have it done. There is nothing wrong with that.
Let them know how often you need stuff cleaned. If one or both of your daughters is like mine, you cannot tell them to go clean. It made my daughter resent having to do it. Instead, I would tell her I needed it done by Saturday and when would she be cleaning the bathroom, for example. If she had a choice in the matter, things went much more smoothly with my reminders.
Ask them what the consequences should be if they don't get their chores done. You'd be surprised what good ideas they might come up with. If dishes don't get done, my son thought they shouldn't get to eat.
Let them know that they no longer have to have a curfew but they need to let you know when they expect to come home. If they will be late, they need to call you. Tell them that you have this mom gene that will worry about them even when they get old and gray. You can't help it. Keep it humorous. Whenever they complain about you being over-protective, just SMILE and agree with them. Say something like, "I know! It just came with the job!"
Any time they throw insults at you (or something that feels insulting or disrespectful) don't let them think it phases you one bit. Just smile and agree or give a sarcastic response. For example, my kids stopped saying anything was unfair, because I repeated the EXACT same words EVERY time until they got sick of it. I said, "You're right! Life is unfair and the sooner you figure that out the better off you are going to be!" I can't wait until my kids start to tell that to their kids... I know they will because it works!
They will see a new mom and will start to give you more respect. They may still slip up once in a while. That's what kids do, no matter how old they get. For the most part, though, they will respect you for calmly setting the rules and not backing down from them.