Hi there!
Jo here, from the Moz Support team.
Updated for 2021 Spam Score --
It's worth noting that a score of 1%-30% is considered a Low Spam Score, a score of 31%-60% is considered a Medium Spam Score, a score of 61%-100% is considered a High Spam Score.
Moz's Spam Score is the percentage of sites with similar features we've found to be penalized or banned by Google (it's not based on the spam score of the sites linking to you). To improve this score I would recommend reading our guide which explains the 27 factors used to make up this score. You can then look at your site and investigate areas you would like to improve on your site:
https://moz.com/help/link-explorer/link-building/spam-score
Disavowing or removing links is not a method for improving your Moz Spam Score. We don't have a way to identify links you've disavowed. Google doesn't make this information available through their Search Console API. Spam Score is percentage of sites with similar features we've found to be penalized or banned by Google.
Cheers,
Jo