Try using a deep socket on the rubber dampers. You need to reach all the way up to get them, because they are divided, with rubber in the middle. You need to be able to reach all the way up against the bottom of the engine. I assume you got the old plate off already....
"Be Always Sure You Are Right - Then Go Ahead" 2005 Honda ST1300 / 2010 BMW F800 Gelände-Straße