Simplify the following text for a Grade 5 native English-speaking person.
Original: Given the difficulties with the original plot , a revised version , with text changes by Arrigo Boito , was first performed at La Scala , Milan on 24 March 1881 .
Simplified: He was helped by the writer Arrigo Boito who made changes to the plot . The new version was first performed at La Scala , Milan on 24 March 1881 .