Hello I will help you with your question,
You will need a pulley remover/installer to pull it off the pump shaft and then install it to the new pump. This tool is part of your chain autoparts store's tool loaner program or can be purchased for about $40.
The instructions to use the tool and included with the tool.
You will have to remove the pump from the engine to have enough room to use the puller.
Let me know what I can do to help you
The pulley puller looks like the one below
I think you need to pull the pump to replace the pulley and this pump is a pain to pull due to the tight access to the bottom bolt which has to be removed from the bottom with a swivel socket and an extension by feel.