Once a custom field is made available, you can edit it following the steps:
Click "users" menu on the side menu;
Click on "Custom Fields"
A menu will appear with all custom fields already created.
Find the field you want to edit and click on the pencil icon, in the right corner.
A window will show all the details of the custom field. Through the menu you can change the field name, the type of answer, the answer options (if any), if you want to make the field available in the app, and if the field should be active or not.
Besides, you can DELETE the field by clicking the red button in the top right corner of the menu.
After making the changes, click on the SAVE button in the upper right corner.
Want to know how to create a new custom field? Click here.