He'll be slow for a few weeks as he rebuilds stamina. Do the exercises and walk. Buy a big wedge that he can put under his back to sleep. It helps relieve pressure on sternum as it heals and makes it easier to roll out of bed. Don't let him lift things over his shoulders for several weeks. Use the inspirometer (inhaling thingee) and the blowing out thing to jiggle his lungs to help break up congestion/phlegm in lungs.

IF HE STRUGGLES OXYGENATING AND FEELS SLIGHT PAIN/PRESSURE IN THE LEG, GET TO ER IMMEDIATELY TO CHECK FOR DVT/EMBOLISM.

Make sure he keeps his heart pillow handy and hug the stuffing out of it when he's needing to cough or sneeze.

It didn't seem to be as terrible as I would have imagined it, but it was a slow recovery.