Help removing a Vanguard starter mounting bolt.

I have a 16 hp B&S Vanguard 303707 which requires a new starter. I can easily remove one bolt but the one towards the front of the engine is very difficult. I could remove the flywheel to gain access to the bolt but don't want to. I note that B&S offer a special tool but it is rather expensive here.
Any thoughts/experience on this?

If I am correct the special tool is a 13mm wobble socket made by Snap On which explains the cost. some of those have a tork spline center for a wrench, and I have found that to be easier to get in there than the socket. I have a set of tork T wrenches that seem to reach those types of bolts better than the Briggs tool.