Detachment is not something you can force unto yourself.
It only happens when you see the truth for yourself.
To be practical,You can work on seeing the truth by:
Keeping the Five Precepts or (Avoid Evil,Do Good)
Reading or studying the Dhamma
Do Good Kamma/Deeds
Lead this sort of lifestyle on a daily basis and slowly but surely true knowledge and insight will seep in.Then you'll start to see a shift in your perceptions and the way you see the world and yourself.Then after your perceptions gradually change,so will your reactions to it.You'll find yourself becoming detached in a very natural and healthy way.Not in a cold,anti-social or unhealthy manner.You will posses perfect
universal compassion for all beings.
We all have varying levels of attachment..some stronger than others.
If i tried to force myself to be detached i'd get frustrated.
The only reason i can be detached is if i recall the pain and suffering i went through before when i was attached to the very same thing then it's more like.You know what, i'll pass.
when you get burnt once don't get burnt again.
" Where there's no wood, there's no smoke".
Life is not a random occurrence, it's all cause and effect. If your attached to something then you will have to suffer because that something will never last.It's the cold hard truth most people have trouble accepting.Nothing stays the same it changes always.always.always.
If you looked back at your life you'll know this is true.
The happiest moment of your life will never stay like that it will change and give way to something else.So what happens ..you suffer..Why? because your still holding on and longing for that moment or looking forward to a similar moment.
Those people who don't suffer are the ones who can let go.They still suffer a bit.But If you don't want to suffer at all
then you'd have let go from the very very beginning.Like even when you first meet or at your peak of happiness.When i first meet the love of my life i fast forward and saw the moment where i'd have to say goodbye.And this is what kept me mindful.Kept me balanced.Kept me ready for the inevitable,for change.Perhaps even more wiser in my interactions and not take advantage of it. This is what it means to be detached.And unattached.You can be loving and caring while dispelling any dillusion that thing will always stay the same.and there's no way you'd be passionate about something you know would not last.you'd be attentive at most.But not overly passionate,obsessed or addicted to it.If you can't see that then you'll get hurt when it changes.it's only a matter of time.Time can give the illusion of stability and solidity.
Remember,Life is like a stream running, it keeps flowing and it never comes back.ever.
so people cause undue stress on themselves by trying to fight the current.Trying to hold on to something.Being attached to something.The funny thing is these people are also changing.so you have something changing trying to hold on to something else that's changing.Your chasing shadows.
Your best option is to cultivate equanimity or a healthy detachment and let go.
Equanimity means good or bad doesn't affect you.
You'll experience peace.
It's okay if your a passionate person just start with little steps until you can naturally see it.Don't fake it.Don't be indifferent.Don't try to be insensitive.You need to really see the truth.It will change and detachment will come to you naturally.Being detached,you can function perfectly if not better than most people stuck in their own self made prison.
Experiencing constant bliss,being at peace,living in serenity,free from suffering,stress,worry and fear is the worth more than being passionate.It is the highest happiness.