I just put a b&m pro stick in my cutlass and had similar issues.
Normally it goes up and stops into second without pulling the trigger,then you pull the trigger and push up into drive.The trigger will lock ,then you just have to slightly move the stick to release the trigger ---now you can push up into neutral. My problem was that I could'nt go from drive to neutal.It just kept skipping neutral from D to N. I adjusted the cable over and over until I switched back to my original gear selector plate(the plate you slip the cable nipple through). Now it goes into everygear like butter.
It turns out I could'nt use the selectors they gave me.Thats way you save ALL parts,Even if your wife says "whats all this junk"I laughed and said"Junk just turned to gold cause it solved my problem"
P.S. It should've came with a piece of paper explaining the way to use the shifter.