Final Cut Express 4 Fisheye Removal

Morning all, i have a SJCAM Sj4000 Action CAM and am looking for the easiest way to remove the fisheye effect from the Video recorded.

I have an old copy of Final Cut Express 4 and am having trouble locating a suitable plug-in / process to complete the job.

Unfortunately, SJCAM do not provide any software directly compatible with the camera, so without spending a fortune, i'd love to turn the challenge over to the experts.

Hope someone can help.

Many thanks in advance.