Matching your tiles will be the problem though in most cases.
Replacing shower pan in tiled shower.
They fit on the floor inside the shower and act like a tub keeping water off the floor.
No point in tearing out entire shower when it fails the issue is almost always just the pan.
Ceramic tile showers that are properly built contain a waterproof barrier shower pan liner under them that catches water transferring through the tile floor and directs it down the drain pipe.
Shower pans are made to work with fiberglass shower surrounds and tiled walls.
If your shower has a shower pan replacing just the pan is possible but not always advisable.
How to replace a tiled shower floor.