Is there any harm in removing the entire bottom casing of my laptop?

My laptop isn't working right and I hold a feeling it's the heatsink/fan. In bidding to seat it clearly I would own to unscrew the whole casing and remove it. Will within be any vandalize done to the laptop if I remove the bottom shell? I've never through it before. I've only unscrewed the casing where the hard thrust is.

Thanks.