I have inherited my Mother-in-law's Christmas cactus. Currently it is potted in a clay like dirt in a plastic container with drainage. The soil is very, very dry and pulling away from the side of the pot. It has been neglected for the last 2 years. It was in a window that gets afternoon sunlight.
It is quite large and beautiful when it blooms.

I need information on the following:

Repotting
Watering
Light/darkness needed for blooming
soil type
pot type
fertilizer

Thanks to any and all who send help.

HKS