How can I convert missions that use Kegetys' Winter Kolgujev to his newer Winter Nogojev Island?

It's not too difficult. Follow theses steps:

  1. Use a tool, such as UnPBO, to unpack the mission PBO file. You should unpack missions directly to your \OperationFlashpoint\Users\your_player_name\missions\ subdirectory.
     
  2. Rename the unpacked mission directory suffix from "cain_snow" to "kegnoecain_snow".
     
  3. Edit the MISSION.SQM file with any text editor and  remove all addon references from all ADDONS and ADDONSAUTO class sections. There may be several such sections. Save the changes you made.
     
  4. Start OFP: Resistance 1.85 or greater and open the mission with OFP's mission editor. Click SAVE and save the mission as either a single or multi player mission, whichever it is. The newly packed mission PBO file will be saved in either OFP's MISSIONS or MPMISSIONS subdirectory, depending on how you saved it.