I have 2 sole proprietorship companies, 1 is a video production company, the other is the company I sell the videos thru. How do I merge the assets into the 2nd company?

Both companies are under my SSN, and since I am no longer producing brand new videos under my production company, I just want to sell what I have already produced through my 2nd (selling) company. However, the equipment (assets) are still required for replicating from the masters to sell, so I want to transfer the assets to the 2nd company that is selling the videos?