First, I would keep everything the same and make it so nobody knows i had taken over for the day and ensure nobody else will tell if they knew. Then I would make the site play “Never gonna give you up” but at a very low volume. Slowly, the volume will get louder until the staff has to address the concern. They can't turn it off or remove it, they can only turn the volume down. However, it starts going back up, at a quicker speed then before. They will have to turn it down again. Rinse and repeat. Everytime it goes down, it goes up quicker and quicker until it stays loud even if the volume was lowered.
Near the end of the day, 30 minutes before midnight, i will gift everyone a collectible with a picture of rick astley with the message “Never gonna give up on you“, purposely phrased wrong.
Finally, I will log into a randomly choosen staff account, and issue a fake apology about the technical difficulties the site has experienced and offer 6 bells as a way to make up for it. I will then delete my actual account and disappear from the site forever, never to be seen from again.
Or you know, give free collectibles idk....