Please see my answer in 

\https://www.odoo.com/nl_NL/forum/help-1/question/how-can-i-hide-system-tray-icons-in-menu-bar-by-the-side-of-user-name-115512

Hi,

• You must have to make custom module.

• Put account module in dependency of your custom module in __init__.py

• Create xml file and do as per following,

Suppose you want to replace Invoicing menu with your custom menu Accounting,

Original

<menuitem name="Invoicing"
            id="menu_finance"
            groups="group_account_user,group_account_manager,group_account_invoice"
            sequence="50"/>

Modified

<menuitem name="Accounting"
            id="account.menu_finance"
            />

- See helpful Links,

How to create OpenERP Module

OpenERP Complete guide for Module Development and Installation