Step #5 in the One Day Morrowind Modernization list
Download the HD version.
2023-12 Note: Please note that starting with Tamriel Data v10.1, the mod is packaged with loose files and the BSAs are no longer required. If you're updating from an earlier version, v10.1 comes with small dummy BSA files to overwrite the old BSA files (this is intentional). However, you no longer need to include the BSAs in your CFG file.