The only instructions I have for you are that you can click on see inside and copy the scripts and paste them into your project! I'm pretty sure I made a mistake or two, so if you want to tell me what they are, just comment down below and I'll be sure to fix it! In ten hours, that is...
Thank you to the Scratch Team! They made a wiki page about this and I actually took two hours to copy down the coding... Oh! Here's the link!: https://wiki.scratch.mit.edu/wiki/Global_High_Scores