Since I'm an Audio Visual type learner, I like pictures, LOTS of pictures...

This is easier to do if you remove the actual drop away from teh bow by disconnecting it at the vertical adjusting slide. (I did not for some reason)

Remove (2) cover plate screws:

Remove cover plate by rotating anti-clockwise to relieve spring tension.

Make note of spring orientation and set aside.

Rotate rest into up, locked position

Then slide the entire assembly to the outside by applying lateral pressure on the arm.

Make special not of the orientation of the square brass locking pin.
It will fit back in any of 4 ways, but will only work in one of them