The best way is to pay someone else to do it. ;)

Seriously, when we did the ones on my Camaro it was a whole lot of
manual labor to get them out and clean up the rubber goo that was left
in there.  I'm curious to see what other people come up with.

IIRC, we used a combination of sawzalls, air grinders, c-clamps, tried
to press it out, tried to pry it out, tried burning them out... what a
production.

Ray

I don't know which operation you are doing, installing new springs or
just new bushings, so the following is general bushing banter...

Sometimes the location of a bushing makes mechanical removal
difficult.  Further that, heavy corrosion combined with the
undesireable steel/rubber/steel cross section of the typical bushing
makes even destructive and forceful extraction difficult.  A common
last ditch method (or first ditch method if you're experienced) to get
the stubborn, frozen cross-bolt out of the center sleeve is to use a
torch.  Have a water hose ready for safety and open all doors if
working inside, as it is the messiest, nastiest repair work you are
likely to ever do to a vehicle.  Blast the bolt head side and the nut
side after heating them to cherry red.  You need to save any reused
parts nearby, so aim is critical here.  Also, the fuel tank(s) is/are
usually near at least one spring bracket.  Fashion a temporary metal
shield between the work and any lines, tank, hoses, etc. for safety.
The bushing rubber will catch on fire too, so that sucks, and it is
hard to extingish.

If you are referring to removing a bushing from a spring that has been
successfully removed from the van already -- you can try various hand
or air chisel bits that are edge sharpened to only grab/cut the thin
outside shell of the bushing.  If you go around the entire perimeter
of the shell on one side and 'curl' the shell metal inward, it will
give you something to pound or press on with an appropriately sized
socket.  Support the other side of the spring with a larger socket or
makeshift press blocks so that the bushing will be able to pass
through during the pressing operation.

You can clean the surface rust off of the inside of the springs with
sandpaper and lightly tap the new bushing in until it is started and
square -- I like to use a soft faced, shot filled hammer first to
limit damage to the bushing flange -- then press or hammer in with
appropriately sized socket placed on the outer sleeve.

Either way, replacement bolts and shackles are a good idea to buy
beforehand.

Toyota MDT in MO