1- Around 9:00 -9:30 go with your file to ETO office in F-8 Markaz.
2- Go to first cabin (window) after entry. He will calculate the taxes as per invoice and write a breakdown on file. Will take 20 rupees and give you an application form, fill it
3- Go to next window (#2 or #3 ask people as I forgot), an official will cross out the invoices in original file and the application form, but will not sign it.
4- Go to next window (#3 I guess) and generate form F of your car
5- Go in the shops at the left side of ETO office, give 50 rupees to the vendors sitting there and show him the file where taxes are calculated. He will fill the forms for you. Get two more photocopies of the filled forms.
6- Now you can deposit the amounts in NBP F-8 Markaz but very long queues. So better go to State Bank (small queues). You can also do it after inspection in F-9 park.
7- Go to Gate 4 F-9 Park (from 9th Avenue side) for physical inspection (takes five minutes).
8- Come back to window 3 again and the official who crossed out will sign the application form.
9- Go to last window (you can request a choice number, some number are for sale on payment, while others can be picked up at no charge. Just meet the ETO he normally enterains people. I had no sifarish, I met him to get same number as was on my other car and he allotted me the same number in next series). For a normal number the guy at the last window will take 500 and give you plates and a receipt for picking up the reg letter.
It is not difficult. Do not listen to any agent, dealer, 3S etc. A little exercise and you save several thousand rupees.