in a similar vein of 13las’ quality ‘Changes Made to the Original Trilogy films over time’ videos listed above… here are Marcelo Zuniga’s insightful youtube videos on the subject, from 2015:-
‘All Changes Made to Star Wars: A New Hope (Comparison Video) PART I’:-
https://www.youtube.com/watch?v=RNbzSH84mj0 - 13 mins.
'All Changes Made to Star Wars: A New Hope (Comparison Video) PART II:-
https://www.youtube.com/watch?v=uvbrVFP_f0w - 13 mins.
‘All Changes Made to Star Wars: The Empire Strikes Back (Comparison Video)’:-
https://www.youtube.com/watch?v=FmWjPoqEhzg - 16 mins.
‘All Changes Made to Star Wars: Return of the Jedi (Comparison Video)’:-
https://www.youtube.com/watch?v=a2obEPFGrMs - 16 mins.
More sources of information on the changes made to the Original Trilogy films can be found in the first post of doubleofive’s comprehensive discussion thread in the Theatrical Cuts vs. Subsequent Releases section of the site:-