How to become a type B person?

First, establish correct self-evaluation.

Think hard about what's most important to you.
Don't measure your life by quantity.Think more about quality.Get rid of some trivial things.You will probably find that you can do less but better.It is more valuable to have those important thing much more than anything.
Give up the kind of world that demands perfection. A superhuman desire to insist on controlling everything in the house,participation in social work, raise perfect children...If you insist on doing so, thenYou will sacrifice your health, marriage and children.

Give sometime to yourself

Second, we could take our time in doing things.

No matter what you want to do or where you go, live yourself enough of time. In that way, even if there's a delay,you won't anxious.

No perfectionism

Third, we should learn to relax.

Don't get angry about unimportant things., such asThe bus was late and the attendant was rude.For the most part, these things do none of your business. Avoid contact with people who often make you angry.

AND , make friends with type B person.