Load the video clip into Premiere, and go to File > Export > Media -- or you can hit CTRL + M on a PC. A dialog box will open, select .JPEG as the export format. See screen capture below.
After you export using this setting, each frame will be a .JPEG image. See below. The .JPEG files will have whatever export settings you chose for the movie, so if you selected 1080 resolution, the .JPEG files will be 1080 pixels. I hope this helps.
