2000ML320 taking out abs brain?

[austent]

behind the fuse box there are two control units; the front is ESP and I believe the rear is ABS brain; I am wondering how in the dickens do you get those plugs off the top to remove the brain; I have replaced the fuse/relay/stop light switch and sent the control unit on the front of the pump off to be rebuilt, got it back rebuilt and still no abs light off. The code indicates ABS pump, going off the forum here, that seems unlikely so I thought I could send the brain off for checking. I just cannot get the darn plugs off. Thanks for any help.