If you don't mind waiting until the 1870's all you have to do is have Henri of Artois, Count of Chambord accept the Tricolor as the French national flag. Seriously, the royalists had a majority in the national assembly, and the Legitimist's and Orléanists had reached a compromise on the succession. The only reason the monarchy wasn't restored is because Henri refused to accept the crown unless France abandoned the Tricolor flag.
I'm serious he refused to become king of one of the most powerful states in Europe because he didn't like the nations flag.
http://en.wikipedia.org/wiki/Henri,_Count_of_Chambord
Alternatively, have Chambord either not get born, or be born a girl. Then Louis Philippe is the lawful heir tot the throne, and the Orleanist-Legitimist divide doesn't arise.