Here is the link for the information regarding VFS:
http://www.vfsglobal.ca/Canada/Pakistan/
and the address is mentioned below:
Canada Visa Application Centre
Bahria Complex IV, 4th Floor,
Main Chaudhary Khaliq UZ Zaman Road.
Gizri, Clifton, Karachi
Email: info.canadakhi@gerrys.com.pk
Go to vfs office with two pictures of you and your each dependents along with passports and the copy of your PPR. They will charge you approximately PKR 1400 per passport to transmit those passports from you to Canadian High Commission and after visa stamping with COPR to you.
you do not need to book an appointment as it's a walk-in service
their timings are 9am-4pm from Monday to Friday.