repairing horsehair plaster wall

[Josh234]

Thanks in advance for your help and patience. I have a really rough (raised) patch of wall in my apartment that I'd like to repair. (See attached photos.) My experience with plaster and lath is pretty limited. But, I've found that repairs over a large (raised) sections don't do too well with just spackling over the top. If it were drywall, I'd just cut it out and replace it. But, I'm a little worried about opening Pandora's box by destabilizing the whole wall. Any suggestions? I'm going for a lot better, perfect isn't necessary.

Thanks again,
Josh

 

[Danny]

I would be opening it up... looks like board to me that has probably cracked and someone has thrown tape over it and tried to hide it....