Is it possible to connect an already installed VW OEM trunk mount CD changer to a new upgrade non-VW headunit?

I want a new headunit with a built in HD Radio tuner, but would rather not have to throw away the already mounted and wired OEM changer in the trunk (and lose it's functionality or have to buy a new matching changer). Is it possible, perhaps with an adapter? -- Volkswagen Jetta 1998, Clarion Premium IV headunit currently installed