you should have a phone no. written in a piece of paper,or you can have it inside your head.
Step2
chek if its the right time to make that phone call.or in case of emergence you can make it at any time.regurdless if its during the day or night.
Step3
pick up the phone and dial the no.and wait for the reply.you will normaly hear it ringing.
Step4
well after some few seconds you will be directly speaking to the person whom you have called!
Tips & Warnings
1.Be carefull that you have got the right no. so as you will not disturb other people,by making a mistakes.
2.Emergence noumbers like police nos. are not put to be joke around with,so you should keep in mind that when ever you dial an emergence no.just make sure that its realy an emergence.