I hope that the best way is to inherit the view.
To replace the field, use the following code example...
<record model="ir.ui.view" id="view_partner_form2">
<field name="name">res.partner.form.inherit2</field>
<field name="model">res.partner</field>
<field name="inherit_id" ref="base.view_partner_form"/>
<field name="arch" type="xml">
<field name="Field1_name_to_replace" position="replace"/>
<field name="Field2_name_to_replace" position="replace"/>
<Code to add the fields>
</field>
</record>
In the above Code,
<field name="X" position="replace"/> remove the X from view.
For more details please refer the https://doc.odoo.com/6.0/developer/2_6_views_events/views/view_inheritence/