general question on site changes I am contemplating

I have a multi-site, with pro on the main site, membership on 4 of the main sites, and all of these main sites(6) have unique domains mapped onto them. I have multiple member sites on the system, all with their own mapped domains.

I want to change the mapped domain and emails on all 6 of the main sites.

So, if I leave the existing multi site domain the same, can I re-map the other 6? I have changed domains on individual sites before. Is it possible to change the mapped domains on these main sites in a similar fashion?

Of course, I would deactivate the pro and membership plugins during this process, but, what other steps would I need to take and in what order?

And then after this is done, I would want to redirect the old domains to their corresponding "new" domains.

Thanks in advance for your help! Linda @iempoweru