Lots of guides on the internet. Do a general search. The procedure will be the same for most twincam engines.
Tools you need:
dial gauge. Idealy with a long flexible holder on a magnetic stand. Its also good to have a custom dial gauge with a curved pointer that clears the camshaft and gets a good angle touching the bucket.
degree wheel
sockets for spark plugs and crank pulley.
allen keys
calculator
pen and paper
there is a way to find TDC more acuarately than the plastic marks. You need a bolt screwed down the spark plug hole...
start taking your readings only after 0.040" or 1mm movement of the valve. This is more accurate that noticing when the valve starts to measure.
You are most interested in where the lobe centre is. You measure this best by knowing when the valve opens and closes (or after 1mm movement). Lobe centre is in the middle of this.
For inlet:
BTDC + 180 + ABDC = duration @ 1mm
(duration / 2) - BTDC = lobe centre position
A normal engine will have the lobe centre at about 110 deg both ex and in. For a hot NA motor you want lobe centres closer to 100 degrees.
A setting at 110 degrees will give a smoother idle, even with "lumpy" cams. A setting at 100 degrees gives more valve overlap, it should breath and give more power in the high rpm range, but will have a lumpy idle.
