Re-activate integrated / bundled Layer Slider plugin

We thought we would not use a slider so we removed the integrated / bundled LayerSlider completely via the theme options. Now the customer do wants a slider, so what are the steps to be able to use this functionality again? Simply modifying the option in the theme options does not bring back the plugin but a lot of pages have already ben created so I can’t start from scratch… As we are using a child theme, should I simply re-upload the “enfold” directory to the themes folder?

Thanks in advance!