There are two ways to rename your project.
Option 1
1. Go to the Merchant Platform.
2. Hover your mouse over one project under Projects.
3. click ... at the top right corner.
4. Choose Rename in the drop-down menu.
Option 2
1. Go to the Merchant Platform.
2. Hover your mouse over one project under Projects.
3. Click View Project.
4. Click ... in the top toolbar in the detailed info page.
5. Choose Rename Project in the drop-down menu.
Related link: How to manage my project