You can only use one of the textures for each character. Use the one you prefer.

Yukari's textures are named "bc_yukarm_t03".
Rename either one of these textures to "da8e7dec3046e43e-c20661d7065f0d57-00001dd3"

Mitsuru's textures are named "bc004_c5_t03"
Rename either one of these textures to "ece8d45c630a33ae-d5c1e5ebf0ec592c-00001dd3"

These will override the game's base textures to the nude version.
Make sure to enable "Load Textures" in "Texture Replacement" on PCSX2. 