exchanging touch panel and SHARE with button position mapping

Vorenus

According to the manual 03.31, it should be possible to swap the touch and share buttons. I enter the button position mapping function configuration mode by holding SHARE+O and then when I try to press SHARE,touch,touch,SHARE as instructed, the button position mapping function configuration mode is prematurely exited at the first press of SHARE. I notice these instructions are preceeded with saying the PS button can simulate other buttons by double click, but it doesn't elaborate on that function. I've tried many combinations and even double clicking the PS button randomly, but nothing seems to work. Are there more detailed/complete instuctions on how to specifically swap the touch and share buttons with button mapping?