My son uses a hand-me-down Toshiba Satellite Laptop and the CD Drive is structurally / mechanically broken.
How hard would it be to install a new one myself?
Any websites for instructions. . .
I’ve installed new laptop hard drives and memory before but never a CD drive. Is it simple enough for me to do or should I take it to a repair shop?

The DVD/CD drive is a module, go on Toshiba Website. You will be able to identify the part number that goes with your model. It is not as hard as laptop hard disk replacement.