I had the same question a few days ago.
Open up the downloaded file like below.
NewUIs_TDC_1_1_0_TheDarkWraith\NewUIs_TDC_1_1_0_By TheDarkWraith\MODS\NewUIs_TDC_1_1_0_ByTheDarkWrait h\data\Scripts\Menu
Find this file at the bottom of the menu folder
TheDarkWraithUserOptions.py
Open it up with Notepad and change the # the current UI Style
From this
# the current UI Style
UIStyle = SH5Enhanced
Too this
# the current UI Style
UIStyle = SH3Style
Then save your changes
Hey presto you will now have the SH3 UI
__________________
|