To edit your Terms & Conditions utilise the What You See Is What You Get (wysiwyg) editor as shown below:
There are editing functions with the text box and you can copy paste your information directly into it.
Don't forget, to activate your terms and conditions for users to see ensure the toggle says yes and click save!
Any edits to your terms & conditions will require users to agree to them at next log in.
Info - you cannot use hyperlinks in this section. If the page will not allow you to save, check the copy you are using and deactivate accordingly.