I decided not to desolder and resolder because
1. Don't have the knowledge or skilled to do it properly.
2. Don't have the time.
3. Too much risk of wrecking the keyboard physically.
So I bought one liter bottle of distilled water, waited until noon time when the sunlight is the strongest, pour the distilled water over the sticky switches and pressed the button repeated, I proceeded to empty the whole bottle over the board and the back. The board was soaked in water inside out, then I shake the water out and left it in the sun for rest of the afternoon. reconnected the cable, test it and it worked like new, the sticky keys are back to normal responsiveness, no damaged to electronic components.
The only thing is that I have now void the warranty by take the keyboard apart.