You should not need a wrench to either remove the valve or to install it. I have never used a wrench on the valves of either my steel 72 or my AL80. I just screw it down until it tightens against the seat, then tighten it as tight as I can with my hand and, finally, bump the knob firmly (but not too hard) a couple of times with the palm of my hand to get a good, final seat. To loosen, bump the knob a couple of times to break the seal, then unscrew it.
Don't forget to lube the threads of the valve with silicone grease or other approved lube before the re-installation.