Assuming that you have other changes in your profile that you want to keep the easiest way is to create a new profile which will use the defaults. You can export the turn popup from the new profile and import it to your existing after you delete the broken group (using the buttons below the group list).
Now the sizing parameters on my popups are huge. I have got multiple problems now. I would rather just restore the default and re setup my HUD the way I like it. How would I go about that?
In the Configure --> Configure Hud window, select your profile and choose Options --> Replace Current With Default and pick the default HUD you want to replace your current profile with and you'll get reset to the default of your choice.