I currently have a VPS (host.mysite.com) and have nameservers registered as follows:

ns1.mysite.com (IP)
ns2.mysite.com (IP)

I registered the nameservers at Domainsite.

My problem. I want to put 'thisdomain.com' on a different server that is set up as (host2.mysite.com)

I'm having trouble changing from 'host' to 'host2' and not getting any help from Domainsite. (they keep explaining how to edit nameservers)

What complicates this is another server I signed up for (host3.mysite.com) also has a registration record.

So I have a mess. I can't figure out how to delete 'host' and 'host3'.

Hm this is a bit confusing.

You have 3 servers, host/host2/host3, with a-records pointing to each server ip for host2.mysite.com etc right?
And you want to delete host/host3.mysite.com a-record?

Well then you can just delete them at your DNS provider, which appears to be yourself, are you using cpanel or something?

Hm this is a bit confusing.

You have 3 servers, host/host2/host3, with a-records pointing to each server ip for host2.mysite.com etc right?
And you want to delete host/host3.mysite.com a-record?

Well then you can just delete them at your DNS provider, which appears to be yourself, are you using cpanel or something?
I didn't create 'A' records at Domainsite .. just registered the nameservers to host.mysite.com, host1.mysite.com and host2.mysite.com

I was hoping that someone who uses Domainsite might know how to delete those entries.

why do you want to delete them anyway ? just ignore them.

some registrars does not allow delete for nameserver at the registry.

also if those nameservers are in use with ANY domain on the planet you won't be able to delete them