1. Drain the radiator, make sure you put have it drain into a container and don't have your coolant thrown about. Those can be toxic to pets and most living things.
2. Fill with radiator flush. Run from 15-30 minutes.
3. Turn off engine and remove inlet hose and check the mesh for debris.
4. Remove debris.
5. Replace inlet hose with mesh and run the engine again.
6. Repeat steps 3-5 depending on how much debris your mesh is trapping.
7. Turn off engine and drain the coolant flush (again into a container) and fill with water. Run engine for 5-10 minutes.
8. Drain.
9. Refill with coolant water mixture 50/50 or pre-mix.
10. Check for leaks on the hoses, sensor fittings, drain plug, and radiator cap.
If all else is in place you'd be good to go.
You may want to leave that mesh in place for a few days, there are times trapped debris will find its way there. But do not forget to remove it after 2-3 days lest it clogs and blows your hose out.
Remember: always make sure the engine is cool enough before you drain so as to avoid scalding.
Also, make sure you use clean tap water, not well water, not river water, not rain water. If you need a placebo, use distilled water.
Thanks for the reply guys. I've come to search about lavramon. Do this by any chance available up here in pampanga? Do anyone knows if there's a shop that offers this service?
Thanks for the diy step. If lavramon is not available here then diy is my next option.