T1 611, 409D, gear shift, screw, or clamp scrapes

Hello guys, I would like to know how I open the rubber cover, which reaches from the switchbar/stick down to the cabin floor, without breaking it. Reason is that underneath is a screw or clamp loose. At full throttle, which is already quite often with my 409 RV this loose part vibrates and makes a really annoying sound. Can someone help me there, Gruss, Michael