Garmin forerunner (by 2 users)

Please teach me on how to open the unit. I will just clean/blow dry the insides. The Power button is stocked up and the unit just keeps on turning on and off by and by. There is no technician in my area. I am living in the Philippines now and GPS things is still not that famous in this part of the world :) . There is nothing I can do. i tried prying the sides but the plastic covering just would not give in. I dont want to force as I dont want to completely ruin the unit.Thanks