Enable the Shield Resource Pack in Your World
Install the Resource Pack
Resource packs are applied at the world or server level, not through mod menus. Download the pack file and place it in your resourcepacks folder inside your .minecraft directory.
Activate in World Settings
1. Open your world or create a new one
2. Go to Settings → Resource Packs
3. Find Drodi's Shield Resource Pack in the Available list on the left
4. Click the arrow to move it to the Selected list on the right
5. Confirm and return to your world
The new shield model and textures will load immediately. If you don't see changes, try closing and reopening your world. You can reorder resource packs by dragging them in the Selected list—packs higher up override those below.
Verify It's Working
Craft or find a shield and equip it. When you hold right-click to block, the shield should appear noticeably smaller and cleaner than the vanilla version. In offhand, it should be invisible in first-person view.