That metal plate is a lift/assist for the machine. Yes, it comes out easily. You can remove the large bolt first that the spring is coiled around and that part comes out and then remove the plate. I always take pictures before I begin for reference to put things back if I want.
The Rocketeer will then fit the hole but there is a modification you need to do to the lip that supports the machine along the front side. Macybaby described it in one of her posts but I don't remember where that was...I haven't made that particular substitution although I have played a lot of Musical Chairs with cabinets.