Hi! Unfortunately, yes, it is necessary, since some of the internal components of the laptop overlap slightly onto the edge of the optical drive. You can use brute force to remove it if you want, but you will likely cause some damage to the laptop casing and/or the internal frame that the logic board connects to.
That said, while it's a complicated procedure, it's very do-able. Just give yourself an hour or so, and keep track of the screws, and especially where the cables route to, because it's hard to remember which cables go under/over/around parts of the metal frame when you are putting it back together. I'd recommend using a digital camera to take a few snapshots of the board and frame during various stages of disassembly so you can refer to them as you put the machine back together.