You don't.
One of my best friends is the younger sister in this situation with a brother 10 years older than her. From her perspective, she's an adult (and has been one for 4 years now) but she's still being treated like a child. Being told not to hangout with certain people. Being told she has an "attitude problem" and she needs to be nicer to her family.
From an outside perspective of the whole thing, it looks to me like a self fulfilling prophecy1. Her parents and brother treat her like she's not an adult, setting curfews and telling her which friends she can't hangout with so she reverts to acting like an adolescent, lying about who she's going out with and having a short temper with them, which just makes them treat her more like a child. Even if she tries to do what they say, she feels like she's giving in and letting them control her. She feels like she's losing.
You cannot change your sisters. You had 18 years2 to try to help raise them and teach them. They're now their own people. They're adults.
As such, quit treating them like children! It'll only perpetuate the circle and push them away from you. They're going to hangout with who they want and they're going to come back when they want. The only thing you can control is how they see you.
Are you the always-upset older sibling who nags them day and night no matter what they do? Or are you a supportive eldest sibling who's there for them, thick or thin. Someone they can turn to when they have hard problems they don't want to tell anyone else about?
I would strongly, strongly consider dropping this. Neither you nor your sisters will gain anything from you trying to control them.
However...
You can still have a strong relationship with them!
If you want to spend time with them but they always seem to be out late with friends, schedule something in advance. You could approach them with something like:
Hey sis, I feel like it's been forever since we just hungout. Did you want to grab lunch/go to the beach/see a movie together some time? I'm thinking maybe next weekend or the week after, when are you free?
Strong relationships are built on trust and support. Right now you're making yourself the bad guy. If you really want to be a big part of their life, you have to accept who they are and be there for them.
Disclaimer: the above is from a Western perspective. I'm not sure how things are in Malaysia, but this is based on my Western experience.
1. Probably more anecdotal than scientific, but Jane Elliott's famous "Blue eyes-Brown eyes" experiment and the infamous Stanford prison experiment both reinforce the fact that the way we look at and treat others can drastically change their personalities around us in scarily short amounts of time.
2. Looks like 18 is when kids are considered adults in Malaysia.