94 Dodge Shadow water pump

I need to replace the water pump on our Dodge Shadow. I pulled the Alternator assy and timing belt covers.
I got to the point where it appears that the lower timing belt sprocket needs to be removed to access two of the bolts holding on the water pump on.
I stopped here because I don't know what I'm up against. Is there a keyway on the sprocket or what?
How is the belt removed and replaced as I don't see a tensioner?
Is there anything I should know about this before moving forward?
Thanks much