Have you checked Youtube for tutorials on how to check if you have the correct drivers install, whether or not the device is recognized by the operating system etc. Have you checked the Owner's Manual to see if there is a hardware switch to turn the touchpad on/off? Another way to double check whether the unit needs repairing is to try booting a Linux version like Ubuntu on the computer. There is no need to actually install Ubuntu as it can be booted and used from a bootable USB stick. See https://ubuntu.com and https://tutorials.ubuntu.com/tutorial/tutorial-create-a-usb-stick-on-ubuntu for more details. It could also be a case that a connector has come loose inside the computer so that the touchpad doesn't actually need replacing. Better to check out all possible solutions as much as you can before starting to take your computer apart.