See the instructions in the file named Proj08.htm in the attached zip file.
By the time you reach this point in the course, you should be able to find what you need in the learning resources without specific hints and pointers.
If you haven't already done so, you need to study everything about arrays that I have published in the following topic areas at Object-Oriented Programming (OOP) with Java.
OOP Self Assessment
Programming Fundamentals
Essence of OOP
Multmedia
You should also study the modules that deal with the Object class and the need or lack thereof for casting.
Also, make sure you understand the meaning of the C++/Java syntax consisting of a pair of matching curley brackets with a comma separated list of items contained in the brackets.
Finally, when you downloaded the assignment, the zip file contained a folder named docs that contains standard Java documentation for my version of the program. You may find the documentation helpful in determining parameter types and return types.