Change leader of tiny organised protest about nothing (10)
I believe the answer is:
transition
'change' is the definition.
(I know that transition is a more specific form of the action change)
'organised protest about nothing' is the wordplay.
'organised' becomes 'tran' (I can't justify this - if you can you should believe this answer much more).
'protest' becomes 'sit in' (type of protest).
'about' means one lot of letters goes inside another.
'nothing' becomes 'o' (looks like zero - 0).
'sitin' enclosing 'o' is 'sition'.
'tran'+'sition'='TRANSITION'
'leader of tiny' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for transition that I've seen before include "Switch" , "Change of state, style, etc" , "Process of change" , "sort of element" , "Conversion" .)