To reduce spam score in link building, you need to focus on building high-quality backlinks from relevant and authoritative websites. Here are some tips:

• Identify and remove spammy backlinks. Use a backlink analysis tool to identify any low-quality or spammy backlinks pointing to your website. You can then contact the webmasters of those websites and request that they remove the links. If they are unwilling to remove the links, you can use Google's Disavow Tool to signal to Google that you do not endorse those links.
• Build backlinks from relevant and authoritative websites. When building backlinks, focus on getting links from websites that are relevant to your niche and have a good reputation. You can do this by guest blogging, creating high-quality content that other websites will want to link to, or reaching out to other website owners in your niche.
• Avoid black hat SEO techniques. Black hat SEO techniques, such as link buying and keyword stuffing, can damage your website's spam score. Instead, focus on white hat SEO techniques, such as creating high-quality content and building backlinks from relevant websites.

Here are some additional tips that can help you reduce your spam score in link building:

• Monitor your backlink profile regularly. Use a backlink analysis tool to monitor your backlink profile for any new spammy links. You can then take action to remove or disavow those links as needed.
• Create high-quality content. High-quality content is more likely to attract natural backlinks from other websites. Make sure your content is informative, well-written, and relevant to your target audience.
• Promote your content. Once you have created high-quality content, promote it on social media and other websites. This will help you to get more people to see your content and link to it.
• Build relationships with other webmasters. Get to know other webmasters in your niche and build relationships with them. This will make it more likely that they will link to your website.

Reducing your spam score takes time and effort, but it is important to do so in order to maintain a good reputation with search engines and improve your website's ranking.