stock_transfer_order/views/stock_transfer_order.xml

<?xml version="1.0" encoding="utf-8"?>
<openerp>
  <data>

    <!-- Override workflow -->
    <record id="sale.trans_wait_invoice_invoice" model="workflow.transition">
      <field name="act_from" ref="sale.act_router"/>
      <field name="act_to" ref="sale.act_wait_invoice"/>
    </record>

    <record id="sale.trans_wait_ship_ship" model="workflow.transition">
        <field name="act_from" ref="sale.act_wait_ship"/>
        <field name="act_to" ref="sale.act_ship"/>
        <field name="condition">procurement_needed() and (transfered == True) and ((order_policy!='prepaid') or invoiced)</field>
    </record>

    <record id="sale_order_form_invoice_credit" model="ir.ui.view">
      <field name="name">sale_order_form_invoice_credit</field>
      <field name="model">sale.order</field>
      <field name="inherit_id" ref="sale.view_order_form"/>
      <field name="arch" type="xml">
        <button name="invoice_cancel" states="invoice_except" position="after">
          <button name="stock_transfer_action" string="Transferencia Interna" type="object" attrs="{'invisible': ['|',('invoice_exists', '=', True),('state','!=','progress')]}" groups="stock.group_stock_manager"/>
        </button>
      </field>
    </record>



    <record id="inherit_view_picking_form" model="ir.ui.view">
      <field name="name">inherit_view_picking_form</field>
      <field name="model">stock.picking</field>
      <field name="inherit_id" ref="stock.view_picking_form"/>
      <field name="arch" type="xml">


        <button name="do_enter_transfer_details"  position="replace">
          <button name="entregar_producto" string="Transferir" groups="stock.group_stock_user" type="object" class="oe_highlight" states="draft,assigned,partially_available,confirmed"/>
        </button>

          <button name="force_assign" position="attributes">
            <attribute name="invisible">1</attribute>
          </button>

          <button name="action_assign" position="attributes">
            <attribute name="invisible">1</attribute>
          </button>


      </field>
    </record>

  </data>
</openerp>