Sorry for lateness But i think this is still an Issue and all above answer are not good.

If you want to completely replace a form.then you have to follow these steps.

1-Write your new form.

2- If you are not creating new action then skip this step otherwise write your action.

                <record id="module_name.action_all_owners"  model="ir.actions.act_window">

                        <field name="name">All Owners</field>

                        <field name="type">ir.actions.act_window</field>

                        <field name="res_model">res.partner</field>

                        <field name="view_type">form</field>

                        <field name="view_mode">tree,form</field>

                        <field name="context">{'search_default_customer':1,'default_owner':1}</field>

                        <field name="search_view_id" ref="view_res_partner_filter"/>

                        <field name="domain" eval="[('customer', '=', True)]"/>

                        <field name="help" type="html">

                                <p class="oe_view_nocontent_create">

                                        Click to add a contact in your address book.

                                </p>

                        </field>

                 </record>

3-If Action already exist or you write above action, define each view type you write in main action type.like

<record id="module_name.action_all_owners_tree" model="ir.actions.act_window.view">

    <field eval="1" name="sequence"/>

    <field name="view_mode">tree</field>

    <!--<field name="view_id" ref="module_name.view_partner_tree"/> -->

    <field name="act_window_id" ref="module_name.action_all_owners"/>

</record>

<record id="module_name.action_all_owners_form" model="ir.actions.act_window.view">

    <field eval="2" name="sequence"/>

    <field name="view_mode">form</field>

    <field name="view_id" ref="module_name.view_partner_form"/> 

    <field name="act_window_id" ref="module_name.action_all_owners"/>

</record>

ID -Must be unique.

eval - Sequence of view type 

view_mode - [form,tree,kanban,etc..]

view_id - ID of new form or tree view you want to replace.

act_window_id - ID of main action on which you want to perform stuff

IMPORTANT ::If you just want to add one new view type like form but not want to disturb sequence then write tree and kanban view with out view_id as you can see in tree view action i just comment view_id so it just only update form view without disturbing view sequence.

Try use this:

<xpath expr="//form" position="replace">

first you just need to give id of view that you want to override in model.

<record id='view_account_analytic_account_form' model='ir.ui.view'>

<field name="name">account.analytic.account.form</field>

<field name="model">account.analytic.account</field>

<field name="type">form</field>

<field name="inherit_id" ref="account.view_form_id"/> // give (view_from_id ) Id of Form View to override form view

<field name="arch" type="xml">

<data> <xpath expr="//form" position="replace">

</xpath> 

</data>

</field>

</record>

Hi Silviaa

<record id="analytic.view_account_analytic_account_form" model="ir.ui.view">

<field name="name">analytic.analytic.account.form</field>

<field name="model">account.analytic.account</field>

<field name="arch" type="xml">

    please place your code

</field>

</record>