Pool return fitting cracked and leaking

I have a return fitting -- brand unknown -- that is cracked where the (male) eyeball holder screws in. I'm not sure if this can be fixed entirely from the pool side of the fitting, or if I must get at it from the deck side by cutting through the concrete.

I also need information on how things are fitted together on the deck side -- presently inaccessible until I dig -- in order that I can decide whether or not to tackle this job myself. I can find no diagrams showing the assembly of one of these things nor can I find a video that shows how to replace one.