Elna Lotus SP : Cleaning the Bobbin Casing/Shuttle Area?

Does anyone know how to clean the bobbin casing and shuttle area? There seems to be a lot of lint trapped between the moving parts, and underneath it, but I just can't get to it.

I purchased this machine second-hand and it was full of lint, most of which I've now removed. It sews a perfect straight stitch, and a near perfect narrow zig-zag, but has great difficulty forming a wide zig-zag and sewing in the far left position.

Any help would be appreciated.