Glad to meet you, Dirk, and welcome to BYC. Often when chickens start breaking and eating eggs, it means they are short of protein. This is especially likely to happen when they are molting. Check the info on the feed you are giving them. You might need to change that.
Here is an
article on feeding chickens during molt
and here is an
article on common chicken problems, which includes tips on teaching the hens not to break and eat eggs.
and one more article,
BYC Lists of Chicken Ailments and Cures
To look for articles on your own:
A. Use the SEARCH button, but use the Advanced Search choice, and select ARTICLES at the top of the box. Just enter your keyword(s) and scroll through your results!
B. I find it helpful to notice the rating and reviews. All articles are by BYC members, and all the reviews/ratings are as well. The ratings help a newbie like me sort the most useful and reliable articles.
C. You can bookmark the articles or posts you think you want to refer to again using that bookmark icon at the top of articles or posts. You can find them again by clicking on your own avatar and looking at the list of bookmarks you have built up!