(Note: The replay might break because it was too precise.) First, you go to the link, paste the level code in the editor, go to the finish line, play the editor, press the level select button, and it will go to level 7. Press the select button, and it will load the custom level. Copy and paste the replay code if you need help. That's all and have fun :)
Huge Credit to @thepurplebanana66 for telling me how to change the wallpaper to a "BIG" costume (P.S. If you beat it, copy and paste it into the comments or forum and credit @TimonUbud; he did a great job fixing the replay code.) Forum Link: https://scratch.mit.edu/discuss/topic/784878/?page=1#post-8189050