My rockerarms are loose on my 2.2liter engine. how can i adjust them?

Adjust the valves when the lifter is on the base circle of a camshaft lobe:

1. Crank the engine until the mark on the crankshaft pulley lines up with the O mark on the timing tab. Make sure that the engine is in the No. 1 firing position. Place your fingers on the No. 1 rocker arms as the mark on the crank pulley comes near the O mark. If the valves are not moving, the engine is in the No. 1 firing position. If the valves move, the engine is in the No. 4 firing position; rotate the engine one complete revolution and it will be in the No. 1 position.
2. When the engine is in the No. 1 firing position, adjust the following valves: Exhaust - 1,3 Intake - 1,2
3. Back the adjusting nut out until lash can be felt at the pushrod, then turn the nut until all lash is removed (this can be determined by rotating the pushrod while turning the adjusting nut). When all lash has been removed, turn the nut in 1 1 / 2 additional turns, this will center the lifter plunger.
4. Crank the engine one complete revolution until the timing tab and the O mark are again in alignment. Now the engine is in the No. 4 firing position. Adjust the following valves: Exhaust - 2,4 Intake - 3,4

You will have to take the valve cover off, ten to one you will need to replace the gasket.
This can be done two ways:
when you have the cover off and the one you want to adjust,rotate the engine until that valve is fully closed, turn the push rod by hand while thightening the nut, when the rod gets snug, but not tight, that should do it. Repeat if necessary.
Now the messy way,
with the engine running, tighten each one down till the clicking noise stops, but turn the nuts slowly, It's messy, cause oil spatters all over.