Clarification: How to add the customize package inside my app in react-native

I have changed a react-native package src component as per my requirement. How can I add that in my app?

(i.e) I have added react-native-floating-action and changed some styles in FloatingActionItem.js and FloatingAction.js file. How can I add the changes inside in my app.

Because If I remove the node module all the changes are gone after installing it again.