Know anybody you can borrow a spring-compressor from?  It can be done
w/o a comp.--actually I've fixed several and have never used a comp.  Seems
like it'd be much easier, but where I grew up, we used what we had, very
little specialty equipment.  s

Bob-the repair is similar to that on your old Camaro but...you can take
a pry bar and pry that horizontial spring down and out of there(be
careful-that it doesn't spring out towards you and don't loose it).
Also I usually can do the uppers without jacking to door but put a
towel or some sort of fender protection between the door you're working
on and the front fender.  Buy your pin and bushing kit from GM or
whomever.  Make sure you notice that there are two(2)different size
bushings-doubt you'd mess that up but...I usually take a pointed punch
or whatever and break them(old bushings) out of the hole if they give
you and problem.  Re-insert new ones(sometimes they don't 'fall' into
place and you have to strategically 'tap' them into place-socket,
screwdriver, vicegrips) run your pin up thru and then(it can be done
without but..)I would buy or rent a spring compression tool-I've got a
couple but don't recall how much-doubt alot but worth every penny.  PS
by the way, that bracket(arm) you mentioned, swings and won't interfere
with the job, just swing it out of the way.  Make sure, though, that
b-4 you run the pin up thru, that 'arm' is in the proper position(swung
in-you'll see what I mean-it wants to be in position after you finally
insert the spring to ride its shoulders on a roller to keep the door
open as you need it open).  Hope this helps-I did a Blazer Saturday
where the problem wasn't in the replaceable pins and bushings, it was
in the 'other' two holes you'll see-had to drill out some and
improvise(another long story but..)but it finally worked out.  Good
luck, JP

Tip... when we did my old Jimmy's pins, we looped straps through the
window opening and around the rafters in my garage.  Way easier to
"hold" the door when 90% of the weight is being held up by the straps.
(you could use rope.)

Ray