grumpf! how to reach *that* engine bolt

Hi there

Little out of ideas trying to reach the upper left (driver's side)
engine-transaxle bolt.

Its that type without NUT (crankcase has a fixed round bolt). So its
meant to be reached from down under...but gosh...the bolt is so close
to the clutch lever...and there is the heat exchanger in
between...can't put any of my ratchets there...

you think that the heat exchanger can be removed? looks like dificult
to me...boh

somebody can enlighten me?

cheers