I hex edited the client using this procedure to set it to 127.0.0.1
https://otland.net/threads/custom-client-8-6-10-xx.212219/
And then remove the popup you see when you login
https://otland.net/threads/tibia-10-98-custom-client.246511/
If you feel up to it you can try it yourself.
http://static.tibia.com/download/tibia1098.exe
This is file is for those just looking to test their server locally.
http://www.mediafire.com/file/g0hyx0ybekfkx0c/Tibia1098.zip
https://otland.net/threads/custom-client-8-6-10-xx.212219/
And then remove the popup you see when you login
https://otland.net/threads/tibia-10-98-custom-client.246511/
If you feel up to it you can try it yourself.
http://static.tibia.com/download/tibia1098.exe
This is file is for those just looking to test their server locally.
http://www.mediafire.com/file/g0hyx0ybekfkx0c/Tibia1098.zip