I have an inspire 2 with DJI CineSSD. How do I remove the write protection, which means I can not delete a recording, or, for example. copy to CineSSD from my pc.
you can't. There's an encryption/control board built into the CineSSD which stops you from either saving to, deleting from or formatting it on a computer. You can only format the CineSSD by inserting it into the I2 and using DJI Go 4 to format it.
DJI have intentionally made it it like that to keep the SSD optimised for use in the I2.