How can I code a full image header in the Taste theme?

I have the taste theme for my website. I’m wanting to change the code so that I can have an image as the whole header, rather than just a logo in the middle.

Can someone help me with this?

ETA: website is remispetsupplies.com.au password: stahpi

Thanks

cannot open your website. could you confirm you website url again?

Hello there

Please share your exact website link so that I can browse it to discuss more.

Regards

Titu