Reeljob: I don't know if it's the same for the Marines as it was for the Army (in 2004 anyway), but in boot camp we had to memorize all sorts of things - Infantryman's Creed, General Orders, Army Song, Chain of Command from Platoon Sergeant all the way up to the president, etc. Most of these things I could have memorized beforehand and it would have made things a bit easier if I would have known them already. Between the sleep deprivation, physical exertion, etc, simple memorization become more of a chore...,
In short:
- Encourage him to PT even harder. This includes push-ups, pull-ups, sit-ups, flutter kicks, burpees, rucking with weight (start around 20lbs and work up to 40-60lbs), ropes climbs, etc If possible, do as much as possible with a weighted vest on. Most recruits will be wearing body armor for the majority of training. It's not only the main muscle groups you're working on, but strengthening all the ancillary tendons, ligaments, and stabilizing muscles you don't even realize you had. It's not so much about being strong, but being tough. There are few people who don't pass because they're not strong enough, but many who fail because their feet are soft and they get major blisters, or pull a hamstring, or get shin splints, or dislocate a shoulder, etc.
- Have him start memorizing as much as possible - Rifleman's Creed, Marine Song, General Orders, Marine Chain of Command, etc (memorize all the rank insignias - you don't want to be calling a Captain a Sergeant...)
- Become familiar with the rifle: cleaning, assembly/disassembly, sight adjustment/zeroing, etc. The Marine Rifle Training Manual is freely available on the internet - use it.