What is the best way to rename Lightning Componets?

You can use dataloader and update records in the table "AuraDefinitionBundle" .The developerName is the field that needs to be updated.

Please note you need dataloader or workbench since the object is not accessible via apex

I just ran through this issue and found that renaming the files in a lightning component, plus all the controllers, is a huge pain. Especially if you are creating a managed package.

What I found to be the easiest was to provide a new label for the component via the design file. This will change the name presented in the UI and requires no file name or metadata changes.

MyPoorlyNamedComponent/MyPoorlyNamedComponent.design

<design:component label="A Better Name">
</design:component>

Lightning Component Bundle Design Resources