How the hell do I uninstall Skywind and Skyblivion?

You have to delete each file by hand.( as to make sure that mess up your other mods

Go to "Skyrim\Data\Meshes\architecture" delete arena, anvil, cheydinhal, chorrol, bravil, Castle, castleinterior, cathedral, cloudrulertemple, daedricstatues, farmfence, farmhouse, godstatues, imperialcity, kvatch, leyawiin, lowerclass, palace, priory, sestatues, sestonewall, settlements, ships, sidewalk, skingrad, statue, stonewall, tents, wayshrine.

Go to "Skyrim\Data\Texture\archtecture" repeat what you did above.

Then go to "Skyrim\Data\texture\armor" Delete the whole folder ( it will ture all armor back to default.

Then go to "Skyrim\Data\texture\rock" Delete folder

Then go to "Skyrim\Data\Meshes\rock" Delete folder

Skyrim\Data\Texture\Clutter" Delete folder(only if you don't have any mod that use it.

Skyrim\Data\Meshes\Clutter" Delete folder(only if you don't have any mod that use it.

Then go to "Skyrim\Data\Meshes\Plants" Delete folder only if you don't have any mod that use it.)

umm... I'm not sure what to do after that

The answer is simple:
If you install something, then you know how to uninstall it as well !