There is two screws whose square heads fit on the column tube that hold the 4" round turn signal part. The "cone" part is held to the round part by two sheet metal screws. The steer wheel itself has a "wire post" that trips the turn signal plastic levers in the round part.

What you have there is very easy to take part, and you should do that to see what you need to do.

By the way, you need to pop the pins out of the connector there so as to pull that bunch of wires up through the tube to allow complete removal of the "round" part.