I have a 1987 rx7 and I just put in a return spring and I was wondering is the shifter goes through the spring hook?

 

take the shifter and tilt the top towards the driver's side,while pushing down with the lower ball on the passenger side of that return spring.
When you push down on the shifter and SLIDE the bottom ball it will allow the bottom ball to go into the shifter block.Do this as you are straightening up the shifter(to go vertical) and it will pop in.
In a sense you are sliding the ball over with the spring and then sliding the ball into the block.
Another thing you may try is to get a Real small screwdriver and wedge it enough in the return spring to bend it back enough to let the lower ball of the shifter drop into the block.It's tricky but doable.