[Hondasucks]

I'm pretty sure there are drain plugs on the engine, you'll need a 17 or 19mm hez socket (I can't remember the exact size, but I'm pretty sure it's 19mm) and an impact wrench. They're usually in pretty tight, you might be able to get 'em with a breaker bar and extension but impact gun is best. Buzz 'em out, let the water drain, pour some clean water in the top, let it run out till it's clear, put the plugs back in. (Might want to put some threat sealant on them) They need to be tight but be careful, you don't want to strip the threads out! Other way is to go get one of those Prestone flush-and-fill kits, they tee into one of the heater hoses, and you connect a garden hose and run it until it comes out clear. It's easier than pulling the drain plugs..