The screws in the end of the shift cable are going to be a problem. If you plan on reusing the cable about all you can do it destroy the plastic guide around the screws and then put a new plastic guide on at jobs' end. The guide part number is -43433.
The steering. Assuming it's not power steering, then you should have the steering cable (from the hem) running through a couple of guides/anchor points. There should then be a link arm from the end of the cable to the steering arm from the gimbal ring. As the union at the steering arm/link arm should have a plastic bushing and be moving freely, I'll assume you mean the connection between the link arm and the end of the steering cable. If it's been maintained properly in the past there should be a castellated nut with a split pin. Normally we remove the split pin and the nut unscrews, the arm just lifts out. But if yours is seized, you are going to need to cut the link arm as close to the steering cable as you can get, without touching the steering cable obviously. Once cut, you may be able to remove the cable from the transom plate and work on the rest of it a bit easier. If it doesn't slide out you're going to need to spin the end of the steering cable and cut the remaining threads off the end of the remains of the link arm, then slide the cable out and punch what left in the steering cable out. A new link arm is part number -68291A2...
Chris.....