Mower deck 2013 Z920 M 60" deck

Are there any special instructions for removing the deck , does the height pedal have to be timed for proper position before removal

Yes,
The deck height adjuster needs to be set so there is little to no weight on it.
Slip some 2 x 4's under the deck then adjust the height pedal so the lifting arms seem loose.
Use 2 x 4's hat are twice as long as the deck so you can slide the deck out sideways once the pins have been removed.