I am happy to report that things have transitioned very well. As with most things, I completely over-thought it and was too anxious about the unknown. Kyle puts him to bed each night and I put him down for his nap each day.
After we would turn off the lights, put on his lullaby's, and rock him in our arms we try to place him in his crib gently on his belly (that's how he likes to sleep). Jack would start to cry each time we put him down. A week or two after he learned what was happening and became much more cooperative. Now when we put him down we tell him "Goodnight, sleep good. I love you". He'll pucker up for a kiss goodnight and wave bye-bye. It's the sweetest thing.
So...it only 15 months, but he goes to bed entirely on his own.