[Lukas242]

Hello, I have tried erasing my iMac following the steps on this thread: https://www.imore.com/how-to-prepare-mac-for-sale#page1

I got stuck on the part where I need to erase a startup disk. In step 2. it says "Click the Erase button at the top of the Disk Utility window.", however, I cannot select the Erase button, since the startup disk is "Fusion Drive". I can however, erase the "Container disk3" that's under the Fusion Drive.

Thank you for help!

[Ed7789]

That should be able to delete your volume. Just make sure after doing so that the space used is close to 0.