It is a way to remove fisheye from a gopro or yi 4k action camera without loosing quality or without replace the lenses ? (regarding the video)
You can, in theory, add supplemental lenses to change the field of view — however this almost inevitably affects quality. Supplementary lenses tend to be low quality.
You can crop the image/video in post-processing — but this reduces quality (at least in terms of number of image pixels)
Replacing the lens is certainly the best way to get a narrower field of view without reducing quality.