How to plug in M.2 SSD?

Excuse me, could you kindly elaborate on the steps involved in plugging in an M.2 SSD? I'm a bit unfamiliar with the process and would appreciate your guidance. Do I need to remove any existing hardware first? Are there any specific precautions I should take while handling the SSD? And most importantly, how do I ensure that the SSD is properly seated and secured once it's installed? Your assistance would be greatly appreciated.