How do you remove and replace the metal sleeved bilge drain hole in the transom? A buddy said the metal sleeve that the plug screws into is put in with some kind of tool. Of course I don't have one and am thinking it's got to be easier than that. Is there a sleeve that fits in like a regular through hull with a nut? How do I remove the sleeve thats there now (it is not sealed/put in properly). Thanx.