You'll need a "pulley puller". Take the pulley off first.

If you're near Thomasville NC you can borrow mine.

Spdloader

If you buy the pump from someone like Autozone, they will
loan you the pulley remover/installer tool.  It is not a
terribly expensive tool compared to the labor for a tech to
do the job.  It is available from most parts houses.  If you
have the plastic pulley, you can get a new one and use a nut
and bolt with a heavy washer to install it.  The plastic
pulleys are cheap and are usually cracked anyway.  Just use
a hammer to bust off the old one after you have the new one.

Lugnut