You can check out this post for some ideas also. Essentially, you’ll need to power the OpenCM904 separately from the DXLs.
First you need these compatible cables to go from the 904 to the XL-430 DXLs
Then you’ll need a few of these X3P hubs also to keep up to 4 DXLs per daisy chain, also separate power supplies or batteries most likely. It is best to design the batteries into your robot’s framing structure, instead of using a big battery, which would be too heavy,
How do you plan to control these DXLs? Via ARDUINO?