You can copy the code from the post, and paste it in a functionality plugin. Then, before to save your changes, replace YOUR_LOGO_IMG_URL in the code by your own logo URL.
Save your changes, and you’ll be all set!
Where do I find the logo URL?
You’d have to upload the image you want to use to your site first. Pick an image that’s large enough (at least 200×200 pixels), then go to Media > Add New in your dashboard, and upload that image to your site.
Once you’ve done so, click to edit the image, and copy its URL.
I hope this helps.
Thanks for your help but I’m getting a fatal error.
View post on imgur.com
Could you try replacing => ; by => in lines 21 through 24? That should do the trick.
After that fatal error happened it rendered inactive the functions.php (according to the plugin window). I tried uninstalling and reinstalling the plug-in but it continues to be inactive. It even loaded the same code I copied into it with a fresh install.
I’m not sure how to make it active again.
Try installing this little plugin I just made for you instead. That should do the trick:
http://i.wpne.ws/cG1h