I believe that it is hard to rid hazing in one grand gesture, but is necessary if it is going to be successful. A strong group in the organization's leadership positions, along with alumni support is crucial.
Also, if you leave some "hazing" in place, you subject new members to those practices, and with an environment of "earning letters through the pledging", the new members will question why they had to do things considered "hazing", while now new members get off easier. Hazing is perpetual, in that what one person had to do to get in, they want the next person to do. If you get rid of it now, in total, you can stop this cycle from continuing.
I hope that's helpful
