Problem 1: The housing cannot simply be pulled off. It's riveted in place.
eReplacement Parts has a YouTube video that explains the problem and shows how to fix it by drilling out the rivets - but the video is for the TB280. There's a button on the lower right of the video that says "Click Here to Get the Starter Assembly Today!" The link goes to an eReplacement page that has lots of parts for the TB230, but not the starter assembly. They have not responded to my query.
So, working on the assumption that I'm not going to be able to find a replacement starter assembly, I went to work to replace just the rope. To get access to the pulley, I clipped out one of the vent dividers (see the photo) and I was able to insert a new rope with knot. But winding back the spring presented a new problem. In order for the tightened spring to pull the rope back into the housing and wrap around the pulley, it must be first tightened in a clockwise direction, and then pull the rope through in a counter-clockwise direction. The spring can tighten by winding the pulley counter-clockwise, but I cannot get it to budge clockwise.
What would be causing this?
Gary
Pull the housing off
Get a starter rope & burn the end making a long point ( ouch that hurts my fingers ).
Wind the pulley till the spring is tight ( ish ) and remove the old piece of broken rope by pulling out backwards.
Slacken the pulley just enough so the hole in the cover is lined up with the hole in the pulley.
Poke the rope through and allow the spring to wind in the rope.
Because I use rope on a roll I go in from the outside so after the spring has unwound I can cut the rope the fit the handle.
If you are working with a cut length then point on one end & knot on the other and work it through from the inside of the pulley.
DOn't forget to undo the dip stick if you have one fitted.