Changing stock heights springs on a
2wd Vanagon usually requires no special tools. Jack, stands, wrenches,sockets,etc..it just takes
a little more disassembling but its pretty easy. Where is gets tough is if you are trying 
to install lift springs or even sometimes the 85 front springs. The typical cheap
spring compressors found at your local parts stores are useless. These
types usually come in pairs with hooks on each end of a long threaded rod. 
They also tend to scratch the coating on the springs. Example:
http://www.harborfreight.com/macpherson-strut-spring-compressor-set-3980.html
The GoWesty lift spring I bought off  another Vanagon owner are a great 
example. He has tried to use the compressor I mention above and
made a mess of the powder coating. He also couldn't get the front spring in
with them as they kept getting either jammed up or something got in their
way when he tried to release the tension. He gave up and because 
he scratched the spings up they were not returnable. 
I researched different options and found a compressor that really works
well but is not cheap. I noticed Aleric from VA (a tool nut) had recently purchased the
same one and gave it a good review. It not only feels really stable and that
the spring isn't going to pop out but makes removing/installing even the
tall lift springs easy. It's most likely cost prohibitive for most backyard 
mechanics but I feel its paid for itself  with the amount of tinkering I do. 
Here is a link:
http://shop.ktcautotools.com/products/macpherson-strut-spring-compressor-bmw-toyota-honda

Like I mentioned its not cheap but its a lot safer. It would be nice if the places that
loan/rent tools had one. Before I purchased it I tried to talk my local tool rental 
store to get one but they had no interest. Maybe over time it will become more
readily available.  Just be careful no matter what you use or how you choose
to remove those springs. When compressed they can store a lot of energy
that can be dangerous if something goes wrong. 

Bill
87 Westy 
Zetec Turbo