He wants to change his son’s name Muhammad to another name, because the name is difficult for the child
Question

                My son’s name is Muhammad; can I change it to one of the other names of the Prophet (blessings and peace of Allah be upon him)? He cannot distinguish between names when they are called, except for easy names like his father’s name, Hasan. Perhaps the name Muhammad is somewhat difficult for him, hence I thought of changing it to an easier name.
Praise be to Allah.
    One of the 
    things that is recommended with regard to naming children is to give the 
    child names of Prophets and Messengers, and the best of Prophets’ names is 
    the name of our Prophet, Muhammad (blessings and peace of Allah be upon 
    him). 

    Shaykh 
    Bakr ibn ‘Abdullah Abu Zayd (may Allah have mercy on him) said: The sixth 
    principle: names in order of preference in terms of how recommended or 
    permissible they are.

     Children 
    may be named after the Prophets and Messengers of Allah, because they are 
    the leaders of the sons of Adam, their characters are the noblest of 
    characters, and their deeds are the purest of deeds. So giving their names 
    is a reminder of them and of their characteristics and stories. The scholars 
    are unanimously agreed that it is permissible to give their names to our 
    children. 

    The best 
    of Prophets’ names are the names of our Prophet and Messenger, Muhammad ibn 
    ‘Abdullah (blessings and peace of Allah be upon him and all his fellow 
    Prophets and Messengers).

    End quote 
    from Tasmiyat al-Mawlood, p. 15-16 

    Based on 
    that, it is better to leave your son’s name as it is; praise be to Allah, it 
    is a good name. 

    With 
    regard to what you mentioned about the child not being able to distinguish 
    the name Muhammad, this is a problem that will quickly pass as the child 
    grows older, and it will not have any negative impact on him at all, in sha 
    Allah. People still call their sons by this good name, in the East and in 
    the West, among Arabs and non-Arabs, and they do not find any problem with 
    that or any difficulties for their children. 

    May Allah 
    make things easy for you and bless your offspring. 

    And Allah 
    knows best.