Changing the worm gear

[sfh]

Hi
I am about to change the worm gear. This time with the mast up.
I have done it once but with the mast down.

Do I need to take any precautions on the furler or can I push it back up when fitting the new gear?

I am aware of the backing plate issue that Ian has described

What else to consider before going ahead?

[sfh]

Adding picture

[moonshadow]

I like to stuff a towel in the mast below the worm gear in case I drop anything like the sail shackle pin etc.