You can find walkthroughs by googling a bit (I myself wrote walkthroughs for the last 4 levels), but I'd highly recommend doing it without cheating. The amount you learn from figuring it out yourself is exponentially more than what you learn from reading a walkthrough. Most important is how you learn to think, by carefully looking for vulnerabilities and examining what you have control over and how the program uses your input.

Spend enough time learning the instruction set and the concepts involved and the answers will become apparent.

Learning to cheat is part of the progress, but agree that at some point Google is not an option.

Honestly really isn't for myself, but based on experience teaching a wide variety of people, that some people learn different ways and are more willing to take something new on if they feel they won't break "it" (which is what the website does) and feel there's a built-in for getting to done. Most users get that connect the dots isn't the same as DIY, but still a option that helps some users that would have never tried, but were interested in the topic. Thanks for commenting.