After a lot of discussion, online and with friends, I decided to get my Vitz' (2012) CVT oil changed from Toyota Rawal Motors, GT Road, Islamabad. This is mostly because this was the closest to my home in DHA 2. I went on a Sunday, so there wasn't many people, but their mechanical section works on sundays.
When I told them that I want the full chamber cleaning method, they tried to change my mind, but I remained adamant. So they started opening up the chamber from the bottom at around 11:30 Hrs.
After opening up the whole chamber, including multiple screws, this much of oil came out:
Note that this is no the whole amount of oil, prior to this about 1.5L had already been drained. A few screenshots from the bottom:
Slightly better bottom view:
This was removed from the bottom and washed multiple times with petrol. The guy was very thorough with his method, and kept rinsing and repeating:
They weren't really sure about which oil to use, but I had done my research and knew that only Toyota's CVT-TC Fluid should be used for these transmissions. After opening the big nut from the bottom, it read "TC", after which they confirmed that the same oil should be used to refill. Part number for the oil is "08886-02105":
Important to note the Toyota Indus seal at the back:
After thoroughly washing, a grinder was used to probably shape the edges and clean the outsides:
Shiny, isn't it?:
Then they started to close the chamber by closing the screws:
This silicon paste was used to put it back after cleaning and washing:
After finishing up the whole re-assembly:
Some other views:
After this, we had to wait for approximately 03 hours. This time is very important as this allows the car to reach at a temperature for the refill process, or maybe some senior pak wheelers may have a better knowledge about it.
So, at around 15:00 Hrs, refilling began by inserting this refilling pipe, and oil was refilled via a small pump assembly:
Again, this refilling procedure was divided into two parts, where a total of slightly over 03 liters of CVT Oil was filled into the transmission. Vehicle was started and Alhamdulillah it did not give any sensor indications or other faults/failures. A total of 03 mechanics worked on my vehicle throughout this procedure. One was the "Ustaad" and the 02 students weren't newbies themselves, and worked pretty tirelessly, and gave useful tips throughout.
The whole procedure took around 4 hours and 30 minutes, and I paid Rs. 5500/- for the CVT Oil with Rs. 3000/- for the labour. I know it's a lot of money, but dealerships usually charge you more, and I was advised to get this done from a dealership. The other procedure of not opening the chamber would be less costly.
Drove the vehicle from dealership to Saddar market to pick up some new mats for the car, and got stuck in heavy traffic. I could feel immediate ease in the shifting of gears. There was some traffic on the way back to DHA 2. After a complete journey of around 45 kms, car gave a total average of 18.0 km/l. I also changed my Air Filter, since it was pretty dirty. Average prior to changing CVT Oil and Air Filter was approximately 14.5-15.0 km/l. Will monitor for a few more days to get the true average.
Lastly, I'm sorry if i skipped other details since I only remembered to take photos once the process had already started. Apologies for any typos, since I typed this whole in one go. Cheers 
