farmerbarlimo

Hi Guys, Im a bit stuck. My phone system has a hold message, which I need to change, the firm we used to use has gone bust! I have got a card reader, I can generate an MP3 file, that I wish to use no problem, but how do I create an SLW file from it an put it on the card, so it will work in my hold messgae thingy! Can any body help please? Thanks Neil