valve clearances on TD

i have a 1989 90 with a TD had it over a year now and decided its time to do the valve clearances. ANy info on how to do this or tips would be muchly appreciated as the haynes manual is pretty vague on how to start!

cheers

Rocker cover off, turn the engine over with a large socket or by jacking up a wheel, stickin it in 5th low range, turning the wheel will turn the engine over (how I did it before I got the socket).

Using the valve checking guide on Haynes you measure/set the clearance of each valve in turn.

You set them to .25mm

cool cheers, haynes manual says something about excessive valve clearances and crankshaftturning. what's it mean by turn the adjuster to eliminate all clearance from any loose rocker arms before turning the cranjshaft to check the vlave clearances?