The three longer screws could be removed with pliers.
The three shorter once I drilled out with a sharp 3 mm drill.
First put tape across the ventilation opening and carefully vacuum cleaned before taking of the antenna plate, though.
Don’t you hate it when the manufacturer does things like this, though??
The server version of the MacMini 2011 has three extra two wire cables for temperature sensors: two on the drive directly under the antenna plate, one on the other drive.
The small connectors have to lifted up from the logic board just like the fan connector and the IR sensor connector.
Take care when transferring the sensors to a new drive because two of those three extremely tiny PC board need to be removed of the old drive and are glued in place.
Indeed important that the power cables are not in the way when reassembling.
Otherwise it will be difficult to get the drive that is directly under the antenna plate back in.