Murphy said that working on the episode had been "incredibly difficult." He talked about how well-liked Monteith had been with the cast and crew, as Huffington Post reported on October 3, 2013.
As he explained, "that group of kids particularly went through the limelight and became world famous at a very difficult age, and many of them really struggled with it. And Cory, obviously, very much struggled with it, but never on the surface, and I think that's why everybody loved him. He was the most kind, the most generous, never a bad word for anybody."
The process of filming was so heart-wrenching that actors and crew members often had to leave the room in tears.
As Murphy related, the emotions in that upcoming tribute are real. "I struggled even working on it, because what you're seeing is what they felt about not just Finn, but Cory, so I think it's amazing performances across the board, and everybody went into it with a lot of love."
He added, "it was rough. It was very rough. It was very rough with Lea [Michele]...but I'm very proud of it. I think the performances are quite stunning. People still are not over it -- it's still very, very difficult."
Finn will be laid to rest in next week's episode of "Glee." This tribute promises to be a tear-jerker. While it will provide the fans with a valuable opportunity for healing and closure, this episode will definitely be a struggle to watch.
Saying goodbye will be the hardest word of all.