Soil pipe connection.When you purchase a new unit, you will probably need to buy a suitable connection piece for the waste outlet. They are push fit connections with multiple fins of rubber to make a watertight seal. There are several different shapes and angles available angled, straight, offset and radiused. The one you chose is dependant on the pipe already fitted and its location in relation to the pan, as well as the size of the pipe itself. Be sure to take a note of the internal diameter of the soil pipe and the external diameter of the pan outlet. Also sketch out the measurements of the distance and offset of the two pieces. If you dont feel confident, then call a professional like Clapham Plumbers .Place the connector piece on the outlet of the pan and move it into position it going in soil pipe. Dont forget to take the rags used earlier out of the soil pipe. Mark the fixing point of the pan on the floor. Remove the pan and drill and plug these if the floor is of a solid type. For wooden floors, drill a small pilot hole for the screws. Remember to check there are no pipes or cabling under the drill holes. Do not fix the pan yet, but line it up again ready.Assembling the cistern.Put the cistern together with all parts following the instruction leaflet and connect it to the pan. This may be with a flush pipe, or the toilet cistern could sit straight onto the pan. Look carefully at the assembly instructions since the correct mounting of all parts is important and may vary from manufacturer to manufacturer.Fixing the toilet cistern to the wall.Ensuring that it is level, mark the fixing points for the cistern, lift it out of the way and drill and plug the wall. A Clapham Plumber can drill and plug. Reposition the cistern and fix. Note that you must use brass screws since steel ones will corrode in the vicinity of moisture. Generally, the screws are mounted through small rubber gaskets to prevent damage. Be careful not to overtighten the screws as the ceramic cistern will crack very easily. If needs be, use some offcuts of small diameter plastic pipe to pack the cistern out from the wall. Connect water supply, overflow, fill and check for leaks