Exactly as shown in the video. In fact by coincidence the figure I used was 2 Mb.
For resizing, by far the easiest way is to use Lightroom export as shown in the video. By setting the number say 2Mb, the quality is adjusted to suit. I always set these figures to match the competition in question and create a fresh JPEG for each competition from the master TIFF file. I suspect that because Phil changed PhotoComp to resize automatically some members did not bother any more so have lost the skills even though the video warns against this. PhotoComp is not being supported after this year so we have to move on.