Navigate Projects> Select Project > Click on 'Go To Workspace' link > Project Workspace > Issue bar in left panel > Click on 'All Issues' > In the workspace area on right side, click on desired issue > Click on 'Attach New file' link as shown below
1. As you click on 'Attach New File', you will see a 'Add Attachment' box as follows
2. Browse through local files or Google Documents /& select a file to attach
3. Click OK to proceed
4. The newly attached file will be shown in Issue View just as above file is shown.