Point 1: scrooge changed and is now happy.

• "I am as light as a feather." (Similie) = juxtaposes "as solitary as an oyster" (similie) it shows that before scrooge was weighed down by his own negativity. Now that he has let his negativity go, he now realises how happy he is. And how free he feels.
• "A merry Christmas" = juxtaposes "bah humbug" this shows that he is now getting in the Christmas spirit and he happy and understands how important it is to be happy around Christmas time. To everybody.
• "Splendid laugh, a most illustrious laugh." = scrooge was always serious. He never cracked a smile. So for him to be laughing shows how happy he now is.