Trouble with Java, I can't figure out how to get started on this problem. How should I go about solving this?

Design a class called Student. This class is used to represent a student with student id, name and total number of units completed in college. Include standard methods (overloaded constructors, gets, sets, toString) and also include a method that determines the student's class standing based on number of units completed, a student's standing is a freshman if completed 30 units or under, a sophomore if completed 31 to 60 units, a junior if completed 61-90 units or a senior (90 units or above) Write out an UML diagram for the Student class. (See a sample in Fig 3.12 on Page 87) Then write Student.java to implement the class design. Write StudentTest.java to create a student object with id as 1234567, name as John Smith, number of units completed as 55.0. Print out the student information including the standing. Then ask user to enter the units completed in current semester, the print the updated information. Sample output: Student information: Student ID: 1234567 Student Name: John Smith Total Number of Units Completed: 55.0 Class Standing: Sophomore Enter Current Semester Units: 12.5 Updated Student information: Student Name: John Smith Total Number of Units Completed: 67.5 Class Standing: Junior