Where can I find a piece for this?

I have Smith&Wesson Sigma 9mm. I recently bought a Blackhawk Serpa Tactical holster. While I am very happy, my father has a Blackhawk Serpa Holster (the one with the button release) but its a side of the leg with a belt and leg strap. I dont want to put out 50-100 Bucks for a new leg holster, is there kits or attachments to convert mine into a side of the leg holster. Please respond