As suggested, you should use late-binding. The standard process is to start out with a reference to the appropriate Excel object library and build your project until the application works as it should. Then, you remove the reference and fix all the resulting errors by using late-binding.

You need to turn Option Strict Off, preferably at the file level and not for the project. You would move any code that requires late-binding into its own file(s) and turn Option Strict Off only for that/those file(s). Next, you replace any Office-specific types with Object. Finally, you replace any constructors with late-bound object creation as demonstrated in post #2.