The tool for this job is a drag link socket. This is a big screwdriver socket that fits the slot perfectly and driven by your ratchet. The one I have is NAPA tool #NB95 and is 11/16 in wide but come in many sizes so bigger could be used
The only tool you need is your hand. It does have an "o" ring seal..why do you need to tighten it down so tight? Hand tight is fine...just like an oil filter..I have never had a leak from eaither area with just hand tight pressure.