mhliu,
In MyEclipse 2015 CI, Matisse can be installed via the Choose Component wizard. Navigate to Help > Choose Components > Expand ‘Enterprise’ section in ‘Not Selected’ column and double click on ‘MyEclipse Visual Swing Designer(Windows/Linux only)’ to move it to ‘Selected’ column > Click ‘Apply Changes’ and restart MyEclipse when asked.
Hope this helps and let us know if you see any issues.