Park the RV is an area you can work comfortably. Prior to parking, take the RV to a dumping station and dump the contents of the old black water containment system.
Put on the goggles, rubber gloves and mask. Turn off all water or other connections to the RV. Go to the back of the RV, where the black water containment tank is held, and open the black water tank panel on the side of the RV. Prop the door panel open.
With the two wrenches, use opposing force on the hose clamp that attaches the black water tank to the toilet and plumbing system. Loosen the hose clamp so you can remove the hose from the existing tank. Let the hose hang to the side and go inside to the RV bathroom.
Locate the black water tank hose on the back of the toilet and use the two wrenches with opposing force to remove the hose clamp. Remove the hose from the toilet.
Go back outside and remove the old black water tank from the RV. Push the new black water tank into the black water tank housing panel. Go inside to the RV bathroom and push the hose down toward the new black water tank and the tank housing. Go outside and grab the end of the hose and slide two hose clamps over the end of the hose.
Attach one end of the hose to the black water tank nozzle. Push one of the hose clamps over the nozzle attachment and hose and turn the set screw on the clamp with the flat-head screwdriver until firm and tight. Go inside to the RV bathroom and attach the open end of the hose to the toilet nozzle. Slide the other hose clamp up and onto the toilet nozzle and tighten the clamp's set screw with the flat-head screwdriver to the right until firm and tight.
Attach the plumbing and turn on the water. Let the toilet fill with water and give it a practice flush. Go outside and push the black water tank gently and listen for sloshing water. Replace the panel onto the RV.