Fitting off a close coupled toilet:
Place pan on floor over the top of and inside the pan connector.
Take rubber cistern to pan connector and place silicone on both its top and bottom. Carefully place it. Then carefully lower cistern down onto top of this rubber keeping an eye on the line up of the cistern to pan bolt-holes, as this is paramount. Then resting the cistern place the bolts and do them up keeping an eye on the gap closing down between the cistern bottom front edge and the pan. You may find you will need a screwdriver to tighten these nuts up properly.
Now with the water shut off to the cold wingback remove the barrel nipple and place the new cistern tap following instructions for the use of nippling brass or brass threaded tubing given under the heading Replacing or placing a tap into a wingback in the wall:
You will need ½-inch (15 mm) threaded brass nipple tube.
Now that you have your new cistern tap pointing upwards measure the distance between the male connections and add 4-inches (100 mm) and buy a flexi hose that is straight and this rough length and install it by first tightening it onto the bottom of the male thread on the inlet feed valve. And then holding against yourself on the flexi hose tighten the other end onto the cistern tap. Fill cistern with water through the tap and flush to test for leaks. Once you are happy with this installation take a white adhesive silicone and with a nozzle cut to a 45-degree angle by about ¼-inch (10 mm) gap in the tip. Work from the very back of the pan where it touches the floor and seal it off from any moisture. Also fill the screw holes, as you will not be using them the silicone will do all the work. Using damp wipes clean off the excess silicone around the pan and off the floor finish.