Moving from LrD to Classic so I can use Topaz Denoise

Just added Topaz DeNoise to my workflow, but find I cannot use it as a plug-in in Lightroom CC.  I would like transition from CC to Classic where I can use it as a plug-in, but when I try to switch Adobe tells me it's not possible.  Part of the move is to switch from the 1T storage in CC to the 20GB storage in Classic.  Any thoughts on how to properly make this simple switch, or where I can find support from Adobe to walk me though it would be much appreciated.  Thank you.