Do it with Davinci Resolve, with the reframe360 plugin, works great. Here is a YouTube video with a top explanation (I learned it there): https://www.youtube.com/watch

The following combination worked for me (with a top-equipped computer, otherwise nothing works):

Convert the .360 files with the Gopro programme (free) and then edit with Premiere Pro CC (costs). There is also another free programme, DaVinci Resolve, which I could never get to work.