Truth 41011 on long arm

This looks like either a 39-253LB or 39-438B to me. The difference between these two operators is shown in the video below.

Hey there. It depends on which operator you have--that will determine how to free up the long arm from under the window sash. If you have the 39-438B with the fixed slider shoe at the end of the long arm you will need to slide it out at one end of the track at the bottom. If you have the 39-253LB then you should be able to pry off the 39-529 off the end of the operator long arm. Try using a flat blade screw driver between the slider shoe and operator arm. You might also be able to slide out the shoe on either end of the window track. Let us know if you have further inquiries. 

Take a look at the video below which shows how to remove and replace casement operators. This is for a different style, but the principles should remain the same.