My doctor said to stay "sub-threshold" of symptoms as much as possible during my recovery, which has been very good bedrock advice. Other good advice:

- The first stage is mental and physical rest until symptoms are gone (or at least reduced substantially). During this period, light activity is OK so long as symptoms aren't triggered or exacerbated. Eventually he'll be able to increase his activity level, but he should promptly back off if he starts to feel worse (don't push through symptoms). Proceed in increments / baby steps. Note: PCS symptom onset is often delayed by a few hours or even a day; it may take him a while to figure out cause and effect

- Be patient and optimistic (rinse and repeat as necessary). The brain will recover if you give it a chance. Try not to worry about timelines for recovery. Be confident in his eventual recovery - he will sense this (just as he will sense worry, fear, pessimism on your part)

- Keep stress to a minimum (look for concrete ways of doing this, such as getting lots of rest, good nutrition and hydration, meditation or prayer, taking a hot bath, creating quiet + pleasant surroundings, etc)

- Create a good sleep environment (dark, quiet, comfortable bed, good temperature, regular schedule, fresh air, comfortable PJs - whatever works) - and keep in mind that he may need a lot more sleep than usual for a while. Sleep is very important during brain recovery

- This might not be for everyone, but I created a basic spreadsheet that allowed me to make notes and track my progress (including a system for rating my symptoms and overall well-being from 0 - 10, tracking my walking times, cognitive work, mood, etc) - I have found this helpful. For one thing, it has shown me how far I've come (very far)

All the best - hang in there.