Open the video in a player like VLC or MPC-HC , which will automatically detect and load the text.
The filename Winterskin.2018.BluRay.x264.AAC-RARBGW tells you several technical details about the video file it is meant to accompany: The title and release year of the film. BluRay: The source of the video (high-definition disc). x264: The video compression codec used (H.264). AAC: The audio format (Advanced Audio Coding). RARBGW: The release group (RARBG) that encoded the file. Where to Find the Subtitles subtitle Winterskin.2018.BluRay.x264.AAC-RARBGW...
Place both the video and the subtitle file in the same folder. Open the video in a player like VLC