All-in-One WP Migration

I searched “all-in-one” and found nothing so I’m hoping for a little guidance in getting the import side of moving my site to VPS hosting on DH.

My site is presently on Bluehost but the domain is registered with Namecheap. Like everyone I’m looking for as little downtime as possible with migrating.

Is there a step-by-step tutorial for this or something similar?

I’m thinking install wordpress on DH first so that I can then install the All-in-One WP plugin and import my site, but to do that I need a domain. If I do “DNS Only” for my site switching the nameservers to point to DH will my site hosted on Bluehost be down at that point? And if “DNS only” is accomplished will I be able to do the one-click Wordpress install at that point?

Thanks a lot, Stephen