Moving from Google Custom Search to Solr

Hello Drupal.

Recently, I’ve installed a Solr search engine and indexed all of our documents.
It’s been a little while since I’ve installed the GCSE and I’m hoping someone could point me in the right direction.

What I want to do is disable GCSE (they’re no longer offering support, besides the point) and enable search using the Solr search I’ve installed.

I’ve already installed the modules on the Drupal site so all I’m looking to do is replace the search functionality with my Solr search.

Thank you and any help is appreciated.

Drupal version: