I use a utility knife with sharp blades. I also use a small pry bar to lift the staples. The carpet can be seen under the slide from outside the coach. Look up under the slide, pull that rubber seal down and the edge of carpet and tile will be visible.
When installing, I measure the widest part of coach and the longest. You can butt the carpet at one wall and secure it and stretch away from that.
Under the slide- you can lift that flap of carpet on the slide and secure the new material.
Going to look weird if you don't replace carpet on the slide, though