Hi there, I too was looking to add the 'Back' button to the checkout pages (even though you can still click on the checkout workflow links to go back). However, after looking at a couple of posts, I have merged other solutions to come up with this addition within the checkout/step.php code just before the </form> tag (hikashop version 2.3.3):
$checkout_back_button = JText::_('HIKA_BACK');
if($this->step!=0){
echo $this->cart->displayButton($checkout_back_button,'back',$this->params,hikashop::currentUrl(),'history.back();return false;','id="hikashop_checkout_back_button"');
}
Also, in order to float it left, I added this to my hikashop stylesheet - frontend_bluegrass.css file (this is just a modified version of media/com_hikashop/css/frontend_default.css):
#hikashop_checkout_back_button {
float:left;
}
And it looks like the other button styles and sits to the left of the Continue Shopping button. Hope this helps others also.