how did you do it?

In the BIOS options of that specific server (nothing fancy, a generic Dell with some Xeon processor) the option to enable/disable ME was just plainly offered. Chipset features > Intel AMT > disable (or something similar, my memory is a bit fuzzy). I researched the option, got worried about the outcomes if someone learned to exploit it, and made it a policy of turning it off. It was about 2 years ago.