I started by taking the couch out entirely.
I added strap hinges to the back of the base of the couch's steel frame. The other half of the hinge attaches to 4"x4" blocks. These raise the seat-height of the couch by 4", but it gives the clearance needed to allow the frame to lift up.
Here's a video showing how it works:
https://youtu.be/4DcZr6YOZKQ
This lets me use the entire space under the couch.
I keep a small stick under there which I use to prop up the couch when I need it out of the way, as you can see there. This last picture was taken some time later, after my new floor. See more on that here:http://b190.com/viewtopic.php?f=2&t=2310