In the Text Editor place the cursor where you want the image
Click the icon The Image dialog will be shown:
Click 'Browse...' The File Manager dialog will be shown: This shows all the files that have already been uploaded onto the server for this particular page.
If the image is listed, select it and proceed to step 6, otherwise:
Click Browse, and select the file to upload from your local file system. The file will be uploaded, and shown highlighted in the File Manager
Click OK The Image dialog will reappear, with the path to the image on the server now filled in.
Adjust any other settings required in this dialog, then