1978 85hp lower unit shift rod problem

[Captain Dan]

I'm rebuilding a lower unit and all is going fine until...... I put the sift rod in.

Two question I hope can be answered.
1. I wanted to changed the o-rings in the piston on the shift rod but I can't get it apart. Is there any suggestions?

2. When installing the shift rod back in it binds and doesn't operate the shift mechanism. Slid out easily when removing.

Help would great! Thanks
Dan