It would seem to me, who am new to T's, that the release latch on the hand brake / shifter should be on the front of the shifter and not on the back.
I cant figure out why Henry put it on the back. He apparently did not have arthritis.
Setting it would be a lot tougher if you were pulling back on the latching mechanism...
It is applied very easily. To take the brake off, pull back hard while you pinch the locking device. You can use the thumb or the palm to pinch the locking device. As soon as the lever is pushed in, hold it in while you move the lever forward. This should work easily unless you have lost use of the thumb.