Hi @CarlyGee,
Welcome to the Bunnings Workshop community and thank you for your question.
This is a relatively easy repair that you won't need a plumber for.
Assuming you have a 50mm flush pipe, then you will just need to replace the seal around the pipe that sits in the back of the toilet pan. This Kinetic 50mm Key Seal is what you would use.
Unless you accidentally hit the flush while repairing, you won't need to drain the cistern, but it might be an idea to disconnect the water supply and drain the cistern just as a precautionary measure.
On the bottom of the cistern, where the flush pipe enters the cistern, there should be a plastic nut. Start by loosening and disconnecting this nut. Depending on how tight it is, you might need to use a pair of multigrip pliers to loosen it.
Once this nut is off, cut and remove the teflon tape that is on the pan side of the flush pipe, then pull it out of the pan. You can then slip the Kinetic 50mm Key Seal over the pipe and push it back into place. Once this pipe is back in place, retighten the nut on the cistern side of the flush pipe, ensuring the washer is seated correctly, and voila, you're done.
Let me know if you have any further questions.
Jacob
