JUst put a new clutch in and i cant figure out where the other part of the shifter return spring connect's too. Right now it connects too the twe brackets coming down which hold the shifter rod into place. I checked the FSM but no good pic of where it goes. Any help please

 

Right under under the shift lever. There should be 2 holes, one on the shift rod and one hole on the opposite side on the support rod

Cant find a pic of a maxima but its pretty similar to this

 

My return spring must be rusting because lately I'm getting sticky movement and weaker return to the central neutral position. It's been years since I installed my STS. Can the return spring be replaced without too much work, or does the exhaust have to come down?

 

You can get to it by removing the cat or your center section of piping. No need to pull the whole exhaust out. The heat sheild has to come off if you still have it.
For me, it was easy to do since I have no cat and no heat sheild.