Char-broil bbq natural gas to LP conversion?

I have a char-broil bbq which runs on natural Gas and need to convert it to LP. Is it possible to just buy a regulator and lower the pressure on the LP tank. I can't find a conversion kit for it. Is it also possible to solder the hole on the jet (orfice) and drill a smaller hole. I tried this on the side burner but the flame was yellow and smoked black. Any help would be greatly appreciated. Thanks