Inserting Google Search Into Thesis 1.8

I am updating my blog using Thesis 1.8 Theme and the minimal skin.

To date I have inserted a photo header and moved the nav menu to below the header using the following code in the custom.php file:

“remove_action ('thesis_hook_before_header', 'thesis_nav_menu');
add_action ('thesis_hook_after_header', 'thesis_nav_menu');”
I appreciate I could also have done that with Thesis OpenHook plugin.

Anyway I am now trying to place a Google search bar in the right side of my nav bar.

I have my Google form code and I assume this is placed in my custom.php file?

I am assuming also that the placement takes place within the custum.css? Can anyone tell me what code to use and where it goes?

Many thaks for your help