The information on this hack is spread throughout a series of posts. The link above goes to the completed programmer (kind of a look back on the hack). But you might start with this post about module firmware options. Just because you can get the part inexpensively doesn’t mean that it’s going to work as you expected. [Byron] sourced similar devices from different suppliers and found they were not running the same firmware; the footprints were the same but he features were not. With his help you can tailor the code to your needs and reflash the device.
The programmer that he build has a nice slot for the module which interfaces with the programming lines using pogo pins (spring-loaded contacts). It connects to the CSR BC417 chip’s SPI pins in order to flash the firmware. If you’ve had any experience working with these cheap parts we’d love to hear your tale in the comment section.