Follow the pad guide. When the pads are off:
Remove the calliper holder from the hub, 2 bolts
Probably best to do this next step before you remove the pads actually - then if needs be you can use the brakes to hold the disc still. Remove the 2 bolts retaining the disc to the hub. They are often seized, a buzz gun should remove them but failing that and other standard methods drill them out. They don't do anything except hold the disc in place while the wheel is off so you don't need them.
Remove disc, hit it from behind while rotating it with a 2lb hammer if it won't budge.
Fit new disc and reverse above.