How do i boot my neighbors off of my century link wifi

Hi @Shell
You can follow the below-mentioned steps for securing the network. 
 
1.  Change the admin password to something with 11 characters or more. 11 characters as a base make it hard for password crack utilities to break.  Having more than 16 is even better.   
 
2. Change the Guest network password or even turn it off when not in use.  
 
If you want you can disconnect any device from the router settings by his device MAC address. You can refer to the router's manual or contact ISP to know how to do it.