Great, everything is working perfectly now. I enjoyed this moment to clean speaker and lens which were so dirty. The only hard step is to remove the back. I advice not using a tool when you’ll unstick this thing, you might damage some component. Separate the back from the phone using your fingers and be very careful to not tear off the mobile computing system. It may remain sticked to the back. Finally, don’t throw away your former head jack before installing the new one. You may have to re-use its flexible platic cover if the one provided with your new headphone jack doesn’t fit in the compartment.
Thanks to the author of this guide which gave me the courage to execute this replacement by myself!