left side cover on a shimano Calcutta 400a

[GeorgeN]

I want to make sure before I do this.  I need to remove the left side plate on the 400a for cleaning and lube
I know there are two very small screws inside the frame that have to be removed.  There is also the larger screw that appears to have something to do with the large nylon idler gear that operates the level wind.  Does that need to be taken out too?  Thanks George Santee, CA