When we introduced my SIL's baby to her dogs they had set up a baby pen/bed for the baby and had been putting blankets that had the babys smell on them in the baby pen a few days before bringing the baby home, then when she brought the baby home her OH was holding the baby whilst she walked in with them, the dogs obviously went to greet her and her OH put the baby in the pen, the dogs were taken to the pen and from that day they were OK with the baby, they still are, you should be making a routine now though. When a baby comes into the house routines will change for the dogs and so if you switch them with the baby there they may put their guard up, but if you switch the routine around now they will get used to it and you will be able to go about it as part of your daily life.