It's easy to be like Simon (6)
I believe the answer is:
simple
This clue is a double definition.
'it's easy' is the first definition.
(similar in meaning)
'like simon' is the second definition.
(reference to nursery rhyme Simple Simon)
'to be' is the link.
(Other definitions for simple that I've seen before include "Easily done" , "Not complex, easy to do" , "The sort of interest" , "Plain and uncomplicated" , "half-witted" .)