Hey,
You would want to look at the translate tools here. tf-mlir-translate has the conversions to/from external formats. For exporting back to graphdef youd want to first run island breakup pass too (there is tf-graph-export registered pipeline which you can use with tf-opt for that and some other passes).
The translate tool is mostly for testing/development so the user experience is intended for that audience (e.g., it has sharp edges). It does show the paths to invoke (and indeed for tflite converter and new bridge we wrap these up in a more user facing package). Let me know if it doesn’t work.
Best,
Jacques