His Imperial Majesty Shāhanshāh Mohammad Reza Pahlavi unfortunately has two Islamic names "Mohammad" and "Reza" despite being a secular liberal individual and leader
However if we were to De-Islamify the names it's best to change the first name Mohammad only since it's more Islamic than Reza and also because we can't transform both names by Iranianize (i.e. Aryanize) them otherwise the full name of the Shāh would become completely unrecognisable at that point if we transform it that way making it impossible to know who is being spoken about in this case the Shāh
The Arabic name "Mohammad" (محمد) which is the name of the Founder of Islam in Arabic means "Praiseworthy" and to translate it into Iranian it will become "Setudeh" (ستوده)
Therefore His Imperial Majesty would be known as "Setudeh Reza Pahlavi" instead
If we were to completely Iranianize (i.e. Aryanize) his name then it would become "Setudeh Khwoshnud Pahlavi" this is because the Arabic name"Reza" (رضا) that is also the name of the 8th Imam of Shia Islam in Arabic comes from the meanings "Satisfaction", "Contentment", "Pleasure" and"Approval" and it's Iranian translation is "Khwoshnud" (خوشنود)
In Conclusion:
To make the name of the Shāh sound completely or very natively Iranian (i.e. Aryan) similar like to the ancient Iranian Monarchs (i.e. Aryan Monarchs) again and less Islamic or not Islamic at all it would become the following...
His Imperial Majesty,
Shāhanshāh Setudeh Reza Pahlavi or
Shāhanshāh Setudeh Khwoshnud Pahlavi
Make Iran Great Again 🦁🟩⬜🟥
Long Live The Shāh Pahlavi 🕊️💜💯
Imperial IRAN 👑☑️
Zoroastrian IRAN 𔓙🔥
Payandeh IRAN 🕊️💜💯
2,500+ years of Iranian Monarchy
7,000+ years of Iranian Civilization