Rear swinging arm bolts

[David-S]

Hello folks,
I have recently refitted my rear sub-frame/diff/suspension back in my 1981 W123 230TE Estate, after fitting new parts including new swinging arm bushes. I have delayed tightening the swinging arm bolts until the weight of the car is on the suspension as per my manual. However now I am unable to get even a standard socket on either the bolt-head or the nut, nevermind a torque-wrench is there a simple way around this problem or is there a special tool required, or am I missing somthing obvious?. This applies only to the outer bolt, the inner one is accessible.

Thankyou David