You simply declare a 'long' variable (or constant) inside your class but outside any method and assign the value to it. You should probably do the same for those 'byte' values. If you have ever declared a variable before then you already know how to do it because this will be no different. If you don't know how to declare a variable then, as it's about the most basic thing you can do in programming, I'd suggest that you need to work through a beginners tutorial to cover the basics first. This is a good one, which will cover far more than declaring variables:

http://www.homeandlearn.co.uk/csharp/csharp.html