Hi,

If you want to disable the create and edit option from the Many2one field, you can update your field by adding options to it.

<field name="many2onefield" options="{'no_create': True, 'no_create_edit':True}" />

By activating the developer mode and clicking the Edit form view from the debugger button, you can spot your field in the view, along with your field definition add this,

options="{'no_create': True, 'no_create_edit':True}" 

For editing the field from the UI, see this: How To Add custom field from UI

For making the change from code by inheriting : Make Changes in Exiting Views

Thanks

If I understand correctly you are trying to hide the Create & Edit button. 

If so, have you looked at this technique? 

\Odoo forum: Hide [ Create and Edit... ] button

It suggests that you set the create and edit attributes to false, like so :

<form string="NAMEOFFORM" create="false" edit="false">