Milgard casement window crank (34" x 46") - right side crank

Thanks for writing in. This is most likely the 39-253LB and 39-253RB Dual Arm operator. Just confirm that the appendage at the end of the straight arm is the 39-529 square-shaped track slide, sold separately. If it is a rectangular shaped track slide instead, let me know. 

For new covers and handles, see the 39-375 and 39-376, or the 39-451 and 39-452, depending on the style you prefer. Let me know if you have any other questions. 

That would depend on when your operators were made. Older operators unfortunately aren't designed to allow their covers to come off; instead, they're permanently affixed. It's only in comparatively newer models where the covers can be popped off and replacements popped back on. 

You'll have to check to see which type you have. If the covers can be removed, you should be able to do it very easily with your fingers. Otherwise, you will need the new covers.