Yes it is under the bed and the plywood is stapled down. Pop the staples loose and take the plywood out. I then cut the plywood in two pieces so it was easier to remove in the future and reinstalled each piece of plywood with screws for easier removal in case of trouble down the line. be advised you can only do this job with the slide in the OUT position. Check all the slide parts to make sure they are fastened tightly to the floor and are aligned properly. I can't remember if you have to take the bed hinge loose and remove the bed to do this job, been ten years since I did mine. Take a look at how you would manually open or close this slide if you ever had to while you have it open, A tough job in my opinion if you ever had to do it in a camp ground with the bed sticking part way under the closet. Lucky I have never had to do it on a trip.
Othertonka
2004 Southwind 32VS 8.1 Workhorse chassis
2002 CRV Toad
U. S. Gear Unified brake system
Retired Fire Captain, SFD