Replace search bar text WordPress

Arnav Joy answers:

find this input box

<input id="s-main" class="field full s ac_input" type="text" onblur="if (this.value == '') {this.value = 'Enter search keywords';}" onfocus="if (this.value == 'Enter search keywords') {this.value = '';}" value="Enter search keywords" name="s" autocomplete="off">

and replace it with

<input id="s-main" class="field full s ac_input" type="text" onblur="if (this.value == '') {this.value = 'Search Here Using Names or Details of Coaches';}" onfocus="if (this.value == 'Search Here Using Names or Details of Coaches') {this.value = '';}" value="Search Here Using Names or Details of Coaches" name="s" autocomplete="off">