C:\games\OpenMWMods\Weapons\ImprovedThrownWeaponProjectiles\Data Files
C:\games\OpenMWMods\Weapons\ImprovedThrownWeaponProjectiles\Patches
C:\games\OpenMWMods\Weapons\ImprovedThrownWeaponProjectiles\glass-glowset

Download both the main Improved Thrown Weapon Projectiles file, and also the optional Glass Throwables patch for Glass Glowset file.

Extract Data Files and Patches from the main file. In the Patches folder, create a meshes folder and within that create a w folder. Place the .nif files from the Patches folder into the w folder you just created. Create a folder called glass-glowset in the base mod data path and extract the contents of the Glass Glowset file into it.