Hi holliwoodhostess,
If you change the text in part of your master profile, those changes will not be automatically updated in your active listings or the saved listings you may have created from that master profile. However, the changes would be reflected in any listings that you load the master profile into thereafter.
In order to change the text in your active listings, you would need to revise those listings using eBay's "Revise your Item" form. Assuming the text you need to change lies within the description, you could just click the "Standard" tab along the top of the description editor on the "Revise your Item" form and make the changes with your cursor and keyboard.
On the other hand, if you make changes to a seller details profile, those changes would automatically be updated in saved listings that you used that seller details profile in. Similar to changes with the regular profiles, changes made to seller details profiles would not automatically be reflected in active listings though.
If you have any other questions regarding your account, please feel free to contact our customer support team using the form on the following page of our site: http://www.auctiva.com/help/requesthelp.aspx
-Mike