I think you said in a previous post that you had the cable off at the helm end and the wheel turned OK? So you don't suspect the helm? You have a Teleflex 4.2 NFB?
Teleflex video for selecting cable length
https://youtu.be/BsHvms0XLic
If you can't get the cable off without moving the motor, you won't get it on without moving the motor.
(if you hack a big hole in your motorwell you
might get it out)
Starting with the cable connected normally;
Disconnect the drag link (stainless bar that connects to motor swivel arm) from the cable. Turn wheel both directions. You say this is hard. Probably the cable..but..
With motor down, Try moving the motor left/right by hand. Verify that it is not hard and that you have grease in the swivel zerk fitting and it comes out from top & bottom when you add more. (I am currently dealing with this problem)
If its good...
Turn wheel until cable is all the way inside the tilt tube.
Loosen the cable from the tilt tube using the big aluminum nut that is "captive" on the cable. You will probably need to hold the cable with channel locks or it will try to twist when you are loosening the big nut.
When the nut is loose from the motor, pull the cable out.
If there is not enough room between the motor and the motorwell, or if the angle is bad, you will get stuck.
Don't force it. If you bend the rod at the end of the cable, you will need a new cable.
Borrow a motor jack, loosen the motor, and move it enough to get the cable out.
Test the cable by turning the wheel with your little finger. if you can't, get a new cable.