Note that the barrel adjuster will (or should) not affect the position of the RD in high gear, where it's resting against the limit screw with the cable slack. Shift to the second position on the lever, and hopefully the RD will shift to the second sprocket. If not back out the adjuster until it does.

Now adjust the barrel adjuster while watching the RD from the back and you'll see that backing the adjuster out tightens the cable and moves the RD inboard. You want the RD centered on the sprocket (the chain runs quietest). Once you adjust it for one sprocket (except high) it's set for all of them.

Now shift through the range, and fine tune the adjuster so that the shift response is equal on up and downshifts and all gears shift crisply (this is usually within 1/4 turn on either side of where you centered it earlier.



Now shift, to