I am not absolutely positive on your particular starter, but most
starters have two connections: one larger bolt and one smaller bolt or
slip on connection. The body serves as ground.
Perhaps look under the hood to see how it is hooked up -- you'll note a
fat wire going directly to the battery. That one is most likely your
larger bolt connection. A thinner wire (the smaller bolt or slip on
connection) goes somewhere else (a harness somewhere, most likely).

On a bench using battery booster cables, connect the negative battery
terminal to the starter's body. Connect the positive battery terminal
to the larger bolt (the one that on your car goes directly to the
battery). To test it, connect another wire (this one can be thin, like
zip cord) from the positive battery terminal to the smaller bolt or
slip on connection -- if the starter is good, you'll note that a gear
inside the starter will move outward and spin.

Be very careful doing this because - if there is indeed something wrong
with the starter - it may not spin at all and throw large sparks
around. The voltage is low so that is not dangerous, but the sparks
could hurt your eyes if it happens to break small pieces of metal
loose. Wear safety glasses to make sure.

Remco