Stream Stay 2 Furler Feed Section

[Sundance0825]

I have a Catalina 34 with a Stream Stay 2 furler. The luff feed section has broken, and I have read that this is a common problem with this product. Rig-Rite has a replacement "parch" for this problem, but my question is, has anyone used this, and and if so, how hard would it be to make the repair with the mast up?

I know it is an old furler and the easy response is to replace the furler, but I would like to spend $300 to fix this one rather ant $3k for an new one. Any advice is appreciated.

Thanks.