Going to have to make some local calls and get at least a couple of prices.
Not going to do you any good with a bunch of "ball park" figures from people that could be from any where on the planet that have never seen the home.
First issue is why did it fall?
Then you need to find out if there is there more damage and does more stucco need to come off?
Photos would be nice.
If you have never done stucco before it is probably not a DIY job. It will look terrible unless you can match the texture and colour.