if your only goal is to basically test if your new used distributor works,
you can test that just by -
rig up a spark plug wire to test for spark,
remove, carefully,  the plug from the side of the distributor in the engine,
plug that into your new distributor.
turn on the key,
turn the new distributor with your fingers.
You should see a zap from the test spark plug wire, and hear the fuel pump
run for a few seconds.

if it does that, it works, basically.
that doesn't test for say, timing curve, but it proves the thing can produce
spark.

changing the distributor in the engine is fairly idiot proof.
It only fits one way.
mark carefully where the old dist is, relative to a nearby spot, so you can
install the new one at that same spot, rotationally speaking.

the drive for it is offset, so it really only will fit all the way down into
the engine one way.

pay attention to firing order of the plug wires of course, buy you don't
need to even take those off the dist cap.

Scott
www.turbovans.com
----- Original Message -----
From: "B Feddish" <bfeddish@NETREACH.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Friday, April 16, 2010 10:52 AM
Subject: How hard to swap distrubuter

>I have a spare distributer from the complete extra 1.9 that I originally
> bought. How hard is it to swap this out with my current one to do a test?
> Is there something I can screw up and cause lots of grief doing this?
>
> Thanks,
> Bryan