Overriding com_contact component in a template - Joomla! Forum - community, help and support

i overriding core component com_contact. 1 of modifications need reducing height of contact message box.
it turns out height impacted value rows="10" defined in contaxt.xml file located in in \components\com_contact\models\forms\
...
<field name="contact_message"
type="textarea"
cols="50"
rows="10"
id="contact-message"
description="com_contact_contact_enter_message_desc"
label="com_contact_contact_enter_message_label"
filter="htmlsafe"
validate="contactemailmessage"
required="true"
/>

this xml definition later used in dynamic generation of html code:

<dd><textarea name="jform[contact_message]" id="jform_contact_message" cols="50" rows="10" class="required">some message text</textarea></dd>

of course possible directly modify core(!) contact.xml set, let's say, rows="5" , solves problem.

but know modification of core code extremely bad practice.

can advise how make override of contact.xml in template directory apply necessary changes , not touch original core file? should located override original core contact.xml


thank in advance.

instead of using overrides.... can set height/width of textarea#jform_contact_message via css