What documents do I need to bring to Chaiyaphum immigration to transfer my visa extension to my new British passport?

The user inquired about the necessary documents needed to transfer a visa extension from an old British passport to a new one at the Chaiyaphum immigration office. They were unsure if they needed to make copies of their old passport or if any additional documents were required besides their two passports, departure card, and a letter from the VFS office regarding the extension transfer. A commenter confirmed that they did not need to bring copies since the office would handle that and there was no fee involved.