It kinda like a puzzle that Indiana Jones would unlock, but really much easier. You may want to have the rear on jackstands and someone underneath to let cha know if its in neutral while you're moving slids around. Its hard to explain and easier to actually do. Was the truck in neutral when you pulled the cover? Its really a matter understanding whats going on inside. Sounds like one of the forks on the shifter is going behind or infront of the "channel " its supposed togo into to. Especially if you are seeing that neatral is Not neutral. Patients and dont force the cover on.
