Havoline XLC orange coolant is available widely as a 1L concentrate bottle.
Mix the 1L bottle with 1L of distilled water (battery water is fine, "AC ka paani" is NOT distilled water) and you have 2L of 50% concentration coolant. My 8th Gen Civic with 200k+ odo runs XLC.
Honda Type II coolant is available in Karachi, but as a premix, and it's best to use to top up a system that is already running on Type II - e.g. an untampered Civic.
Yes you can do the fluid change yourself. Remove the thermostat, run a garden hose through the entire system to clean it out, close the system up, refill with coolant, bleed the air out of the system, check for leaks. Run the engine to operating temp, top up overflow reservoir as needed after cooldown.
Search the forums, there is a lot of great info, including how to flush the system and clean deposits using citric acid.
