Rear shock replacement - 91 Jetta (Mex)

From the shock I removed the rubber snap-cover, the nut and large dish
washer -- but recessed into the upper rubber bearing is another nut that
requires a 17mm wrench.

Though I'm sure there is a special tool available, I'd appreciate any
short-cut ideas on how to remove it. I think it's unlikely that a cut-out
socket (like the 21 / 22 mm used on the Front Struts) is used -- there's
only about 1/2" clearance between the top of the shock piston rod and the
speaker shelf metalwork.

Thanks!

Jim