Well uhm... first of all you'll need a web server. Maybe your company has one server of its own or you can hire some.
Next you'll have to create an html from where the users will be able to click and download the classes. (I assume you'll want to download the .class not the .java, because otherwise those who download it would have to compile them).
Then you save that document as an html and place it in the server. In the same directory, you have to include the classes (class1.class, class2.class, class3.class, etc).
You can also create a JAR out of all the classes and then upload it as only one file instead of the others. However, that would depend on whether you want that to happen or not
. To create a JAR, you have to use the jar command