[SOLVED] How to run Lemmy Account Migrator?

I've heard about LASIM a few times now, this great tool for migrating Lemmy subscriptions from one account to another. I downloaded it from Github recently to try it out... only problem? I have no clue how to get it to run. All the instruction I read online just say "run LASIM" as if it's that trivial and leave me feeling silly.

Can anyone explain this in terms that I (not an experienced programmer) could understand? Am I missing something really obvious?

Edit; I'm on Windows if that matters