You will need to go to see SP officer in Karachi. Fill application form in Urdu and English. Passport copy (1-5 pages). National ID card copy. All your address details from Birth and submit all documents there. they will give you one week time. during that time couple of police man will come to your home to check. Give them rs.500/-. then go back to SP office and collect your report. If you are not in Pakistan ask your Father, Mother, Brother or sister to do that for you. Make sure they take their ID card with them.
go to sindh police website if it's site still working you can download guide from there.
tell your dad or brother, go to headquarter polic station and get help from like police peon and he will charge approx Rs.3000.00 between Rs. 5000.00 and bring next day to your home.
good luck