You might want to make sure the valve has enough clearance to remove it before ordering you may need to order a new floor mounting seal too.
The valve slides out and the new one slides in for replacement. I have a slight dribble from mine due to a leaky seal in the valve. I tried to slide it out but it hit the wall before completely sliding out. That riquires removal of the toilet from the floor in order to completely remove the valve. I've got all the parts but haven't had time to do replace it yet.
I can't remember if the floor seal came with the replacement valve.