Edit Channel- coil_def.dat

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please if someone did it before please help me:
the idea is I load the fif file and I have the 2 file as you see in the attached image raw and channel, if I export them to matlab it seems to be its extension name .edf and .pos respectively
the idea is to make them again as .fif file
I am interesting to load the fif file so that the info in the coil_def.dat can be integrated after I made the changes in the channel file
Thanks in advance