I am a new Knownhost customer. Need some advice on transferring my domains from other host to here. The primary domain I signed up here is the same one I used in other host, a reseller account. And 3 other domains residing on it. All domains/sites are owned by me. What are the steps to move my primary domain and other sites here, if I change the primary domain DNS to new ones, other sites on previous host will be down during the propagation right?