procedure and specs on adjusting rocker arm & valve train on 1999 mazda 626 LX 4 and6cyl---- adjusting lifters also

2.0 liter:
Testing and Inspection

VALVE CLEARANCE INSPECTION [FS]

Remove the cylinder head cover.
Verify that the engine is in cold condition.
Measure the valve clearance.

(1) Turn the crankshaft clockwise so that the No.1 piston is at TDC of the compression stroke.

(2) Measure the valve clearance at A in the image.

Standard [Engine cold]: 0.225 - 0.295 mm (0.0089 - 4.0116 inch)

If the valve clearance exceeds the standard, replace the adjustment shim. See: Adjustments
(3) Turn the crankshaft 360°clockwise so that the No.4 piston is at TDC of the compression stroke.
(4) Measure the valve clearance at B in the image.

If the valve clearance exceeds the standard, replace the adjustment shim.
Install the cylinder head cover. Refer to Timing Belt; Service and Repair.

2.5 liter:

Testing and Inspection

VALVE CLEARANCE INSPECTION [KL]

Remove the intake manifold.
Remove the cylinder head cover.
Verify that the engine is in cold condition.
Measure the valve clearance.

Turn the crankshaft clockwise so that the No.1 piston is at TDC of the compression stroke.

Measure the valve clearances at A in the figure. Standard [Engine cold]: IN: 0.245 - 0.315 mm (0.0097 - 0.0124 inch) EX: 0.265 - 0.335 mm (0.0105 - 0.0131 inch)
If the valve clearance exceeds the standard, replace the adjustment shim. See: Adjustments
Turn the crankshaft approx. 240°clockwise so that the No.3 piston is at TDC of the compression stroke.
Measure the valve clearances at B in the figure.
If the valve clearance exceeds the standard, replace the adjustment shim.
Turn the crankshaft approx. 240°clockwise so that the No.5 piston is at TDC of the compression stroke.
Measure the valve clearances at C in the figure.
If the valve clearance exceeds the standard, replace the adjustment shim.
Install the cylinder head cover.
Install the intake manifold.

Try www.autozone.com for the step-by step guide along with pictures for this procedure.
Once at the site identify you car under the heading "current Vehicle"
Next click "Repair Info" on the tabs below the AutoZone logo.
At the middle of the page go to "Your Ride, Your Guide" and click "Become a member" set you username and password
Log-in and click "Vehicle repair guide"
Select the category for the repair needed.
Select (on the left) type of repair needed.
Page opens to your repair info.

you'll also have to look into renting the special tools needed to replace the vifter bucket shims.
some parts stores will rent them, call around.

Try www.autozone.com for the step-by step guide along with pictures for this procedure.
Once at the site identify you car under the heading "current Vehicle"
Next click "Repair Info" on the tabs below the AutoZone logo.
At the middle of the page go to "Your Ride, Your Guide" and click "Become a member" set you username and password
Log-in and click "Vehicle repair guide"
Select the category for the repair needed.
Select (on the left) type of repair needed.
Page opens to your repair info.

any luck yet?

http://www.mazda626.net/topic/29562-how-to-valve-clearance-check-and-adjust/

Has pictures (if they show on your computer).

Be sure to use a new valve cover gasket when finishing up.