Here's a link to the velonews videos:
Click on the "How-To" tab to get to the cross vids.
Go to youtube and search for "superprestige" and watch how the pros do it.
For clothes, do what works, but nothing very baggy. For cold weather I just use those poly base layers you can get at the local camping store, even under my shorts -- since the race is so short, chafing isn't an issue. This season I'm wearing bibshorts to help prevent droop -- because droop can be a problem on the remount. But normal shorts work fine too.
Practice your remounts as much as you can stand before your first race. But use a cheap saddle because almost surely you will bend the rails.
Don't blow yourself out on the first lap. With all the excitement and adrenalin, it's a big temptation. Get a snappy start, try to avoid pileups, then do your work. The nature of the course means you'll be spiking your heart rate fairly often, but you can't spike it the entire time (unless you're incredibly fit). 45 minutes sounds
short, but it can feel very long after you've popped.