How has Stevens changed in The Remains of the Day?

First of all, you need to be clear on what your assignment is. Are you writing an essay? Are you supposed to comment on the section you described?

In any essay, you need to take a stand and use quotations from the book to back up, explain, or illustrate the point you want to make. Don't just throw them in for the sake of having a quotation. Start with a guiding question, such as "Does Lord Darlington really respect Stevens?" and use quotations that help to answer that question.

Since you disagree with Stevens's belief that Lord Darlington would never embarrass or degrade him, then you need to find other instances in the book where he is not treated fairly. You might point out that the fact that Stevens is a servant could be considered degrading by some people. Look back through the book and see if you can find other examples like the one you've given.

First, you need to be sure of your purpose in the paper.  Every paper you write should be your ideas--not just a bunch of quotes from elsewhere tied together with a few buts, ands, and therefores.

What is your main idea?  What are you trying to get across to the reader (are you saying that Stevens did or did not change)?

THEN, what are your reasons for saying this?  You should have a minimum of 2-3 strong reasons for believing your main idea is true.  What reasons are there to prove that Stevens changed? Didn't change? 

Once you have this basic outline in mind, then you should take a look at the quotes you want to use.  Keep in mind that you should never just fill up space in your paper with a quote that is 1/2 page long.  You don't have to use an entire quote, either.   Based on your main idea and the reasons you state for believing that main idea to be true, which quotes from the text in their entirity or in part, will most likely help you prove your point?

Check the following websites on flawlessly integrating quotes into your paper with the use of ellipses, etc.

In The Remains of the Day, what differences are there between Stevens in the first and last chapters?

I think the main difference between Stevens at the beginning and end of the book is that, in reflecting on his past, he is aware that Lord Darlington, to whom he devoted his life, was not the great person that Stevens believed he was.  I also think you are right, however, in concluding that Stevens, despite this realization, has not changed much at all.

As a butler, Stevens believes that the best thing he can do in life is to "serve a great man who does important things" (see enotes link below).  Darlington was that man for him, and Stevens, who served him unquestioningly, feels that from his own perspective at least, he has done his job well.  Although he now realizes that Darlington was a Nazi sympathizer and pawn, he concludes that "the hard reality is, surely, that for the likes of you and I, there is little choice other than to leave our fate, ultimately, in the hands of those great gentlemen at the hub of this world who employ our services" (Day 6 - Evening).  Even though he now sees that Darlington's leadership was not always good, Stevens does not fault himself for having followed him.  As Stevens admits early in the book, he has "a reluctance to change too much of the old ways" (Prologue July 1956).  For Stevens, to efface himself in service of the "great men" remains his ultimate and unchanging standard.