How Do I Use DigitalOcean As My Nameserver?

I didn’t really know how to title the question because it’s really more than what I titled this post, but that’s what explanations are for I guess. Here’s what I would like to do.

Someone very adept as fiddling with DNS records would be ideal for answering this question.

Here’s my topology so-to-speak.

I have a domain that I would like to split across two hosts. Here’s SPECIFICALLY what I mean.

I want to host example.com at one host and sub.example.com at another (DigitalOcean).

Now, as I understand it (it’s been years since I have messed with DNS records), I could achieve this by doing the following …

Setup my registrar’s DNS records like so …

example.com => IP of host1 sub.example.com => IP of host2 (DigitalOcean droplet)

In order to pull this off, I would have to tell the registrar that I want to use their nameserver. That would be step one. Then, configure the DNS records as shown above.

I’m just really not sure how I would do this.