fighting subframe captive nut: need advise

[Konstantin Bogach]

Hi listers.

I need to change subframe bushings. I don't have garage but I have all
pleasures of working on parking lot. The danger  of loose captive nut is
what I fear.  I am thinking of going to my mechanic (who is good
mechanic but not familiar with Audis) and ask him to try all bolts and
if they go out I will do it in my "garage". If if they don't then I'd
like to ask him to do necessary repair (cutting body and replacing nut,
if I correctly understood the procedure from several threads).  My
question: can it be done with all parts in place? If not - what should
be removed to be able to do that job?
I never did this job and I don't see any comprehensive schema in the
Bentley to get an idea.

Thank you in advance.

Konstantin Bogach
East Winsor, New Jersey
200tq '89
200tqa '89