How to reduce website spam score?

If you're using a tool such as Moz to check your spam score then they don't have access to the disavow tool within google search console. They are looking at all links as that is the only information they have.

The only true way of lowing this score is to get the links removed physically. 

Just to inform you that Google doesn't consider Moz spam score while ranking websites. So, you don't need to worry much. However, if you still want to work on the score, then there are certain factors that affect spam score, such as Image, links, content, etc. You can search on Google and find out the specific issue.

1. Avoid usage of spam sensitive words and phrases.
2. Use normal text inside hyperlinks, instead of the URL.
3. Use a proper from address and subject line.