This sort of “encryption” (it’s not; it’s just encoding) is very, very easy to decode. In fact, in order to be usable, PHP has to be able to do it itself, automatically. `eval()`, which takes a string and treats it like php code, is how this stuff “works.” If you want to see what the code *is*, you need a function that takes a string and prints it.
Therefore, just replace the word `eval` with the word `print`.