I drive a '97 Mazda 626 - 4 cyl. Changing your timing belt is not a small task, and it will not be identical to your car (unless you drive a 4cyl 626, mx6 or ford probe with an FS series engine). I wrote this for my 626 community www.mazda626.net and I am copying things here (so some stuff might sound a bit off)....
Welcome my fellow auto DIYer. First, I commend you for taking on this task, I will rank this as one of the more difficult things in the realm of the 'shade tree' DIYer. The hardest thing to deal with is tight spaces, other than that the task is straitfoward for the most part
Step 1: Background Parts and Tools
First off, this is a non-interference engine design. That means that the lowest point that the valves reach is HIGHER than the highest point the piston can reach... A pretty nice idea because if your timing belt breaks for some reason, you'll avoid the cost of new valves and tearing down the head.
I did not have to replace my T-belt, my water pump died and because replacement involves removing the T-belt, I did so as a precaution.
Tools and Parts:
# New Timing Belt
# New (or reman) Water Pump
# Tensioner Spring
# Tensioner Pulley (if higher mileage)*
# Idler Pulley (If VERY high mileage) *
# VC Gasket*
# Gasket Scrapper
# Torque Wrench **
# Jack, Stands, Wood Blocks
# Black RTV sealant (I do not recommend "Ultra Black")
# Metric Allen/hex Key set (Or 1/4" - may require sanding to fit)
# Plastic Baggies and Sharpie
# Piece of Cardboard
# Feeler Gauge Set ***
*If you have the ability, wait and see if the old one is still good - I changed at 74K miles. My tensioner had play in the bearing but my idler was in great shape.
** Highly recommended.
*** Perfect time to check your valve clearance for you guys with solid lifters (98+)
The 93-97 model years used hydraulic lash adjustment (HLA) as opposed to solid lifters used in the 98-2002 design. Both work just fine, but HLA's can clog easily causing valve tap. Its just cosmetic and several frequent oil changes clear it up.