Change bike pedals - Gary Fisher Hoo Koo E Koo

Rob, check the links.
Parts for Life Fitness Bikes Pedals Battery Pedal Straps SPORTSMITH net

VP Exercise Bike Replacement Pedals 1 2 Stationary Bicycle Pedal Set with...

Exercise Bike Pedals

Pedal Assembly for all exercise bikes

Go and buy a Pedal Wrench (at your Local Bike Shop, or online).
If you buy it from your LBS, then they'll happily demonstrate how to use it, otherwise do a search for Bike Wrench on You Tube.
Hope this helps.
Rgds,
Scott

There are so many types of pedals. I recommend that you'll get a pair that you know and you are comfortable with. Or you can also check for reviews on pedals and take the ones with the highest rate. However, you should remember that what's fit some people will not necessarily fit you...
Check this link: http://www.vitalmtb.com/product/category/Flat-Pedals,20

Raise the seat to a height where when your pedal is at the bittem of a stroke there is about a 20-25 degree bend in your leg. Also pedal with the pedal's axl on the ball of your foot. If you can change speeds, the smaller the cog in the FRONT the easier it is and the smaller the cog in the BACK the harder it is to pedal. If you still can't get it right, take it to your local bike shop for tips and adjustments. Don't be afraid to ask for help from a bike shop. Bike people love to help others with biking stuff.

Your bike must not be the Cruiser pictured - that's a one-speed bike. So here's a general description--- For gear changes on multi-speed bikes, where the chain has to move between different size sprockets, the chain must be moving in order to shift. So, yes, you have to be pedaling, but it works best if you pedal very lightly - so that the chain is moving, but is under very light pressure. On the other hand, if you have a 3-speed bike where the gear changes take place inside the hub of the rear wheel, the wheel should be moving, but the chain should not - so you should be coasting to change gears.

just move the gear levers, but keep pedalling forward while you do. you cannot change gears while the bike is stationary and do not pedal backwards while changing

If the pedal is moving too free,but the bike are still moiving forward, it simply mean you are using to low a gear .

Try changing to a high enough gear to satisfy your required tension. Be advised that,
You will also increase your speed,and decrease your hill climbing in the process though.

Change the screw or huddle hardly the screw.