Using the enlarger color head and lens as your light source, you could contact print the slide onto 4x5 slide film, or you could make some sort of a light-tight box to hold roll film, and contact print the individual slide onto a small section of film, repeating with a different slide until the roll was filled.
If you have the Pentax 67 camera and lens, you could buy (or make) an extension tube for the lens and photograph the slide on a light table with appropriate color correction, or even use the enlarger color head turned upside down as a light source.