You're getting compile-time error, because the
m.values() is a collection of
Strings. That
ArrayList constructor needs a collection of
Employee's.
Java doesn't know how to convert a String to an Employee. You need to do that. You probably also need to code a loop that will go through all the entries in the map.
It might help if you write down all the individual operations you need to do on a piece of paper. And then start to thinking about converting these steps to actual code.