All you have to do is...
1. All you have to do is to push the button and wait.
2. All you have to do is to sign here.
3. They promised that all I have to do is to tell the truth and leave.
A: Do you know how to play go?
B: It's easy. All you have to do is to use your pieces to surround the opponent's pieces and then take over all of his territory.
A: But I heard it is very difficult to play.
B: It's easier said than done. When you actually play, it can be very frustrating1.
As1 a matter of fact2...
1. As a matter of fact, we were just talking about you when you came3 in.
2. As a matter of fact, I was4 the one who did5 it.
3. I finished6 it yesterday, as a matter of fact.
A: I wish I could7 unsay the sharp8 words to him. He must hate9 me very much.
B: He doesn't mind10. As a matter of fact, he's very pleased11.
A: Really? Oh, thank Goddness!