After going into the AdminCP, Selected Customizations, Localization, languages, then selecting Translation Tools, and turning on 'Quick Translating'. I'm now able to edit the actual header on the main page by long clicking 'Donate' in the header of the plugin, it opens up to allow me to edit the header, and it is saved.
Not allowing the header in 4.0 to be edited may have been a bug and was resolved in 4.0.1, or it was because the option was added to the plugin?
Is there a way to add a PayPal icon to the text. I tried adding my code from my 3.4.7 Donate Sidebar, and it just displayed the text?