How do you adjust timing belt on 1989 Mazda 323 4 cylinder?

To adjust the timing belt on a 1989 Mazda 323 with a 4-cylinder engine, first, ensure the engine is off and the ignition key is removed. Remove the timing belt cover to access the belt, then align the timing marks on the crankshaft and camshaft to ensure they are properly positioned. Loosen the tensioner bolt, adjust the tensioner to achieve the correct tension on the belt, and then retighten the tensioner bolt. Finally, recheck the timing marks and reassemble the timing belt cover.