If you're on the deprecated Starter or Growing Business plans, you can transfer your subscription to another Zeplin user who is on the Free plan from the Billing tab in your profile on the Web app: https://app.zeplin.io/profile/billing
Transferring your deprecated plan will transfer your billing information and any projects you own (both active or archived).
Your plan will then be downgraded to the Free plan, and you can own only one project. Learn more about the Free plan here.
☝️ If you're on the Team, Organization, or Enterprise Plan, you can transfer the workspace ownership from the "Workspace Members" page. Check out this article for more details.