How to convert old activiti data to camunda

hello
i migrate from activiti to camunda but Unfortunately old activiti process in cartable does not go forward whereas new process that i created after migrate is ok and go forward and end.
in database i just change field BYTES_ in the activiti.ACT_GE_BYTEARRAY table as follow:
download files at the above address that were activiti, and open with camunda modeler. so camunda modeler asks you that: Are you sure to convert to camunda?? and i click yes and save and finally replace camunda files to activiti files in field BYTES_ in the activiti.ACT_GE_BYTEARRAY table.
I wanted to know what other changes need to be apply in database?

Did you follow a migration plan? What versions are you moving form?

No. Do you have migration plan step by step?
Version 7.13