You will either need a T10 torx bit, it has to be quite long.
Use your Torx10 bit in the holes circled below
and on the same two on the other side. The screws are quite far in.
Put your fingers right on the edge as pictured and pull slightly towards you.
The whole housing containing the speedo will now be loose and can be lifted from the car.
Unplugging The Speedo
Push the top clip in, this allows the lever to be swung over and the plug to be removed.
Disconnecting the black connector from the rear of the speedo can cause
the speedo to revert back to kilometers but is usually only on older cars.