I'd say there are several things to do but he has to want to participate.
1. have him read the BW book (s) /- at least key parts that you select for him so he "gets" the philosophy behind it, the key techniques (there are some good announcements on the site that outline shh/pat, PU/PD etc in clear wording), and the structure of the day...and what kind of "cues" to look for (you can point out things as you go - like "it took me a while to realize but when Flick gets all jerky with her arms and legs she is actually really getting tired and we need to start getting her calmed down and ready for her nap" etc
2. ask him to commit to being at home one weekend for all naps and that maybe on Saturday he could shadow you while you handle a couple of naps and then Sunday if he feels ready he can try everything from windown to settling to resettling (if necessary)
3. involve him in "A" time so he gets a feel for himself of how much your lo can handle and what her cues are that she has had enough / getting tired / needs change of scenery, etc
the trick is to make sure he realises that you are learning as you go and do not have all the answers either - but you need him to get to know what her cues are and her temperment and how EASY works for her because she will look for consistency and, although resilient, would be better off if dad also stuck with what she is used to when mom is "in charge"
HTH, good luck!