Loose Wiper Arm Control Assembly

[Rally240]

I have just bought this car which is in nice shape.About the only thing I'd like to fix is to tighten the passenger side wiper arm yoke coming through the cowl. It's loose and I can't tighten it by tightening the wiper arm itself.Is there a way to get to the arm assembly and maybe tighten it from below?

As it is every time I open the hood it clips the wiper arm and scratches the paint.

Thanks in advance.

1991 240SX 5sp KADE