1. From Setup, enter Snap-ins in the Quick Find box, then selectSnap-ins.
2. Select the snap-in deployment that you want to work with by clicking the arrow beside the deployment name and selecting View.
3. Click Edit next to Live Agent Settings.
4. In the Additional branding section, click Edit.
5. Set your pre-chat images.
6. Set the width and height of your snap-in. If you don’t make any changes, the default sizes of 320 px and 498 px are used.
7. Set the base font size for your snap-in.
8. Click Save.