1988 Chevy Silverado driver's side door

Hi Merlin
Sorry I wasn't very detailed; my stepdad's driver's door does open from the inside. But it will not open from the outside however.
He said the control rod/wire is about the same size as a #9 wire. It has a hook on the end. It goes down to the latch on the outside edge of the door (black plastic latch which isn't broken), but he said that the control rod veers off into a square, then back. The window guide is behind it and is getting in the way of hooking the rod back up inside. A local mechanic told my stepdad that a special tool is needed to do this in order to get to it and do it. My stepdad would like to know if there's a way to do it without having to buy the special tool or take it in to a shop.