Can I change just the terminal connector piece or do I have to change the whole cord?

Question

From previous question when I stated the cord connection piece was broken on the positive terminal

Answer 1

Just changing the end connector is a temporary fix.  If you do it that way to get to work, you need to fix it correctly soon.

Answer 2

Sure, you can change out just the connector, it's easy and cheap.  You may want to replace the whole cable if you're worried about chemical infusion into the insulation.  I usually don't.