Go to Edit > Prefereces > Addons and search the addon by name "modifiers". At this moment you can choose your favourite modifiers.

If you have a older version of this addon you need to uninstall it before and close Blender, in order to remove some caché files.

Like every addon. Go to Edit > Preferences > Addons and press the button "Install" at top-right corner of the window. Then you need to choose in your computer the addon's zip file.