You don't need this guide until you get to the boss. Go do it then get back here.

Do the usual thing until you get to the lock opening. Pause the game and hover over your friend, the core file deleter.
Then, unpause and double click. After you double click, there'll be a popup which asks if you want to delete the core file. When you first see it, pause the game again, because silly little Azazel likes to ruin your fun and close the popup. Now, hover over the option that says "Yes", because that's what we want to say.
Unpause then double click again really quickly. If done right, you should see this:

Congratulations! You skipped a not-so-major part of the game! If this worked, and none of your private parts got stuck in the toaster, don't forget to leave a 5-star rating and to favourite this guide. If your privates did get stuck in the toaster, comment why and I'll tell you where you went wrong. If Daniel Mullins was a spoilsport and fixed this (which is very unlikely), let me know!