How to start?

Starting JExcel:

If you already have JExcel installed in your Jira instance, just click on the tab JExcel on the main menu bar and you can start using it.

If JExcel is not installed yet, you can find some useful information here: Installing and Upgrade

After opening JExcel, you will see a Quick tutorial panel to know how to use it

After checking the dialog, you can create a new workbook.