Well his daytime routine seems good to me. It is a typical age to transition from 3-2 naps and when this happens they'll probably regulate to being 2, 1.5 hour naps. They tend to do this on their own by fighting the last nap of the day to the point where you give up. Are the naps in his cot?
Re the bedtime routine, I'd change it slightly so that you give the milk downstairs then upstairs, teeth brushing if he has any, grobag, book and then bed. The distance between milk feed and sleep is to help break any feed to sleep associations that may be there.
For the next step, the goal would be that you put him down wide awake in his cot and then leave him to it. What happens if you leave? Does he get upset? You can just try him to see what happens. You can then either inch closer to the door every other evening (gradual withdrawal) or you could do a bit of controlled crying.
At 6 months i'd do intervals of 1 min, 2 mins then every 5 until he goes to sleep. When you go in to reassure him that you are there, you leave him in his cot but just say, 'it's time to sleep now' or similar, quick bum/tummy rub, then go.
Does he have any nighttime milk feeds? I'd say that depending on how solids have gone, a bedtime feed at 7, a dreamfeed or one more in the night should be enough. I'd limit yourself to this number and for all other wakings, I'd settle as above.
Consistency is key so for naps, do a similar routine of upstairs to bed, curtains closed, nappy change, gro bag then bed and settle in the same way.
Hopefully this will help.