The first step will be creating an Enterprise Search Site. To do this, follow these steps:

1. Navigate to the SharePoint Admin Center (https://admin.microsoft.com | Admin centers | SharePoint).
2. Click Active sites.
3. Select Create.

4. On the Create a site page, select Other options.
5. In the Choose a template dropdown, select More templates:

6. Fill out the Title and Web Site Address fields.
7. Under Template Selection, select the Enterprise tab and then select Enterprise Search Center:

8. Select a Time Zone, Administrator, and Storage Quota. Then, click OK.

Once the site collection has been provisioned, you can move on to the next step: swapping the new site with the old site's address.