An invoice can be edited simply by editing corresponding notes (time/expense entries) by going to "Cases (Projects)" -> selecting the case beloging to the invoice. Alternatively, the invoice may be deleted and recreated. After editing one or more notes that were previously added to the invoice, simply download the invoice again. No other action is needed. 

Note that a note included in the invoice cannot be removed from the invoice. If there is a need to remove a note from the invoice, delete the invoice, then delete the note and recreate the invoice.

PDF and Word format invoice documents are created dynamically.  That is, you may change information (such as time/expense entries, client information, case information or firm's information) without deleting the invoice.  After changing information, simply click on the PDF or Word icons in the invoice listing to download updated documents.  

Payments to invoices are also updated dynamically.  After recording a payment (full or partial), click on the PDF or Word icons to download updated invoices showing payments.  

Note that Word invoice is really a HTML file. You may change the extension to .html to open the file in a browser.