I've not done DNA testing, so this might be a bit beyond my capabilities, but from what I've read, you should be able to:
Go to your own profile, click the pulldown menu for My WikiTree and click on DNA Confirmation
In that page, go to your section and click on DNA Tests
Where it says "Add A New Test", use the pulldown to select which test you took, add any comments, and click the big Add Test button.
I think that should add the new results to your profile, if I understand it correctly.