Re: steering cable
Welcome to iboats. I will try to help and it is not too hard to replace.
It must be disconnected from the motor end FIRST and sometimes (about 75%) the motor needs to be unbolted and slid over to the side of the transom for clearance.
The FIRST test is to disconnect the stainless steel arm that connects the cable to the motor and try turning the wheel...... that arm needs to be disconnected anyway to remove the cable. There is a large nut where the cable enters the steering tube and that needs to come off too.
That shaft piece (shiny solid piece) is part of the cable might need to be hit with a brass drift to remove it and they are notorious for getting stuck...... DO NOT mushroom the shaft end.
Once that is disconnected then you need to disconnect it from the helm......
NOTE: It is also not uncommon for steering helms to fail. If it is the helm it will have to be replaced too.
There are basically two types of helms...... Rack and pinion which is normally 4 bolts to remove and easy or there is the rotary type which have a release bolt or button then the cable comes out.
The cable length should be printed on the cable and it is a cable number either followed by a two digit number or the last two digits.
Once you determine which type of cable you need or maybe the whole system they are available here
Boat Steering Systems