Take number 1 plug out, put your finger in the plug hole turn motor over manually preferably, when piston is at top dead center it will blow air out of number 1 hole.
1 exhaust and intake. Each pair of valves should be adjusted when the cylinder is at the TDC of it's compression stroke.
With #1 at TDC you can adjust 1,2,5,7 intake and 1,3,4,8 exhaust.