Mine had screws in the white part on the front edge. They were glued down as well. It had a sheet metal backing to it and was a pain to get out. I started with a flat nail bar and hammer to get the edge up. Then I used a 4' pry/wrecking bar to pry up, slide under, pry up and slide under pry, etc... It bent the stair treads up but I got them off. Hope this helps and good luck!!
Just getting started on short bus build...
2007 Collins (Chevy Express 3500)
LMM Duramax Diesel 4L85E Transmission