Sounds like the plastic pipe seal is still in the frame, if you remove the grease nipple (no longer needed) and the seal will come out. Nipple undoes with a small spanner. I would then fit new BB and replace nipple with a small bolt to secure the cable guide under the bb shell. I think from memory you will require a M5 at bout 6mm long. If you fit the grease nipple back in it will foul on the cartridge BB and rip the frame. If you dont have any M5 bolts put an old v brake spacer on the nipple before you fit it and that sould do you till a bolt is sorted.