How do i access one more system administrator to deactivate it for this Control Access to the Org module

Hello@Sampriti Gopisetti, 

Please check prerequisite :-Before You Start

• Important: Use the new Trailhead Playground that you created for the hands-on steps and challenges in this module. Using an existing Trailhead Playground might cause problems completing the challenge.
• Visit Setup | Company Settings | Company Information | User Licenses to verify that you have one remaining Salesforce license available.
• If you already used both of your Salesforce licenses, deactivate one to complete this challenge.
• https://help.salesforce.com/s/articleView?id=sf.users_permissionset_licenses_view.htm&type=5