The command is simply npm uninstall <name>

The Node.js documents https://npmjs.org/doc/ have all the commands that you need to know with npm.

A local install will be in the node_modules/ directory of your application. This won't affect the application if a module remains there with no references to it.

If you're removing a global package, however, any applications referencing it will crash.

Here are different options:

npm uninstall <name> removes the module from node_modules but does not update package.json

npm uninstall <name> --save also removes it from dependenciesin package.json

npm uninstall <name> --save-dev also removes it from devDependencies in package.json

npm uninstall -g <name> --save also removes it globally