When H was born last year, i was getting a 1yr old, 2 yr old and 5 yr old to bed on my own...along with a newborn. It gets easier with time......
I would concentrate on the older one first - feeding, bathing, teeth, book, bed. I know this time of night can be the worst for newborns - where they just want to be fed/suck, but i found the rocker a saviour.
Once the older one was in bed, i would then concentrate on the newborn. I didnt bath newborn at night....i always did it in the day. Plenty of time to get the routine happening later, my main goal was to get both kids into bed at a decent hour.

I would always be at the point of when putting the older ones to bed...newborn was ready too - just had to be fed. In the first few weeks, leftovers, slow cooker meals or beans on toast was all we had. Cleaning the kitchen, washing up, etc etc was left till all kids were in bed. As hard as that was for me to do, a sleeping well baby was (and had to be) more important at that early stage, than a dirty saucepan.

I found if you put everything else aside - cleaning up, phone calls (oh gawd, a phone call from a friend/family member just throws the whole routine into chaos, dont answer the phone), even your meal, all can wait till babies/toddl are in bed....

GL - i was FREAKIN out about putting 2 to bed when i had my DD#2....now, 2 nights a week i put all 4 to bed and really dont think anything of it....