You should fill the shock to about a 1/4 incha above the top do what boydie said and work the piston. Then let it sit for about 5 minutes after the bubbles are gone or most of them are. Top off until its 1/4 inch from the top again and compress the shock until the oil reaches the top and screw the cap on. If you compress your shock all the way with the spring off it should come out about half an inch by itself. Any more and you run the risk of blowing the shock cap off on a hard impact.