I suggest making sure you update the color scheme, logo and favicon for starters. You can use any image related to your business as your main photo and if you can create multiple images, it is not too difficult to create animations or moving images.
The most important part of your Help Center is content. Not only will that feed your SEO efforts organically, but it will also let your customers know you're relevant and know what you're doing!
Start with an easy set of FAQs and build it from there.
An easy thing to do is monitor your tickets for subjects your customers ask about again and again and use this as the basis for your next short article. Remember, it's great to have everything in one article, but it's better to separate it into digestible chunks and include screenshots if the material is complicated.
Not sure how to tease out what your customers are interested in? Create a custom field for Topic with a drop down for your Agents to populate as a mandatory field and feed it into your Insights Analytics fueled by Good Data.
If you're not sure how to update your Insights dashboards, contact me!