How do you change a timing belt on a 1989 Mazda 626?

Wrong car

Here's a web page that shows how to do it on a Mazda Miata, which is bound to be somewhat similar and somewhat different, but it should show you what you're in for if you attempt it:

http://paulstrovsky.20m.com/TimingBeltChange/TBPart1.htm

I just did my first timing belt change...my advice do a i did and replace the idler, tensioner, and tensioner spring while you're at it. First, remove batter power. Second remoce the plug wires. Remove the power steering pump, with the hoses still atached. Next make sure the engine is supported and remove he motor mount. emove the head and gasket. Neext the right wheel and splash guard. Remove the tension via the teniosner with a Allen wrench. put on the ne belt and reassemble.