How to propose a change in a prayer?

How can I go about proposing a change in a prayer? Or how can I have the change approved by the Catholic Church or their theologians? I'd like to change the prayer of Hail Mary from: > Holy Mary, Mother of God, pray for us sinners, now and at the hour of > our death. to > Holy Mary, Mother of God, pray for us sinners, now and at the time of > temptation. The current prayer doesn't cover the time between when we pray(now) and the hour of our death. I think the prayer will be much more effective if we say **at the time of temptation** instead of **at the hour of our death**. I think "**at the time of temptation**" cover the hour of our death too. I don't think God is an ogre who waits for the hour of death to test us. I don't see much of a significance in the hour of death. If you live your whole life faithfully you should have enough grace for the hour of death. I just don't think that God will judge us based on our decision we make at the moment of death. It is not supported anywhere in the Catholic Chuch teaching either so I don't even understand the reasoning behind putting "**at the hour of our death**" to Hail Mary in the first place. I know it was added by someone in the past but it's not clear who added it and why.