First, this is not an encryption, when you’ll have finish this level, you can take a look at some threads in the solution section that explain it more clearly. And @Coffee.exe is right, you need to figure it out by yourself.
It’s hard to explain without giving a big part of the solution. It’s not encrypted, so you can’t decrypt it, but you have to retrieve the original data in some way. I’m sure Google can help you.
Ho yes, forgot about it. Don’t put yourself in trouble, I don’t know the laws of your country, but if you could avoid jail that would be great. I’ll PM you direct links (tell me if you can’t access those).