Hi @bethanyvaughan,
Thank you for your question and welcome to the Bunnings Workshop community, it is fantastic to have you with us.
You should start by cutting away any silicone from around the outside of the shower tray. It is likely there will be a bead running around the top lip of the tray along the tiles and on the bottom edge of the tray to the floor tiles. This can be done with a utility knife. Please ensure you take all reasonable precautions, such as gloves and long work clothes to minimise the risk of lacerations.
The next step is to work out whether the bottom row of tiles runs over the lip of the shower tray. If this is the case, it is likely that the bottom row of tiles will need to be removed using a pry bar. Once these tiles have been removed, it's possible there is a flange with screw or nails through the flange into the studs. If this is the case, these fixing will need to be removed.
Then you'll need to work on removing the waste. This will need to be cut out using either an angle grinder or a dremel with the cut off wheel attachment. The waste will need to be cut along the inside of the pipe below the shower trays surface.
Once the waste is cut, you should try lifting the edge of the tray using the before mentioned pry bar. If you find that there is quite a bit of resistance, it is possible that the tray has been concreted in place. If this is the case, grab a hammer and hit around the surface of the tray with a fair bit of force. This will help break the bond between the concrete and the shower tray, allowing it to then be lifted.
Let me know what you think and if you have any further questions, please don't hesitate to ask.
Jacob
