It's not too hard to rebuild calipers.  A little messy and time
consuming, but not hard.   If you are in a hurry, why not just
replace the entire caliper?   New ones are $130 from busdepot.com

Hardest part in rebuilding is removing the piston, you may need
compressed air to help.
see
http://www.pelicanparts.com/techarticles/911_caliper_rebuild/911_caliper_rebuild.htm
for tips. (single piston caliper on your 88 is much easier to remove
than dual piston designs)

Step #7 (pedal holder) is a great idea, it will help your master
cylinder from emptying.

If you don't have compressed air, try this:  remove the caliper from
the wheel and remove brake pads but leave the hydraulic line
connected.  Place rags around the caliper where the piston will
"land" when it comes out.  Then wrap the whole thing in an old towel
(to catch fluid).  Have a helper press the brake pedal and the piston
will pop out (keep fingers well away).  After you remove the flexible
brake line, plug it with a golf tee or similar so it won't leak.
Leave cardboard on the ground so you don't pollute the street with
brake fluid.

Use something like a scotch brite pad to clean the piston and
cylinder.  You'll go through a can of brake parts cleaner to clean
everything, use a very fine needle/corner of razor blade to remove
the inner piston seal.  (be careful not to score the cylinder).

-paul

>Hi Folks,
>My LF brake caliper isn't in the best of shape, and I'm considering  going
>with one if the repair kits that various vendors sell.  Has anyone out there
>done this? Mostly I'm trying to figure out if it'll be possible (or worth
>it) without a lot of specialized tools, and with a fairly quick turnaround,
>since this'll be a curbside NYC operation.