Why is your question for a Honda in the Toyota catagory?
On this car, you need to have the Timing belt changed every 100,000km or else it may break and wreck the engine.
The Fan Belt aka Drive Belt aka Serpentine belt can be changed easily. First, find a new belt at an auto parts store... Canadian Tire or Auto Parts Source or UAP etc...
Next, with pleanty of light and perhaps a mirror on a stick examine the belt path of your engine. Draw it so you won't make a mistake, there is usually a drawing in the engine compartment, but it might not be correct, verify it first.
Next, find the belt tensioner, it's a pully usually just a plain flat wheel that rides the flat part of the belt (not the ribbed side). It will have a bolt in the centre of the pully, typically you turn this bolt clock wise (tightening) to cause the pully to swing on it's spring arm to release the tension on the belt. Find a good ratchet or S-Wrench (if you are tight on space) to turn that bolt. Pull the bolt, don't force if it doesn't move. If you have to pull more than say lifting a 2 year old kid then STOP and get help from someone that knows your Honda engine. Otherwise, while releasing the full tension of the belt, remove the old belt from any of the top pulleys (easy to reach). Release the wrench slowly, don't get hurt. Remove the belt completely. Replace with new one around all the same pulleys. Leave the top pulley for last. Once everything looks in place, pull the wrench again to do the last (top) pulley.
It would be great to have another set of hands (& eyes) helping you.
Good Luck!