Avoid failing partial clone in pinned prep installation

README.md

@@ -69,10 +69,15 @@ python -m pip install --upgrade "certifi>=2026.10.19"
 
 # RFD4-Proteina was merged into Diffusers on 2026-10-20 and ships in the next release.
 # Until that release, install Diffusers from git:
-python -m pip install git+https://github.com/huggingface/diffusers git+https://huggingface.co/nvidia/RFD4-Proteina-prep@c9959efdebd75ac7fe9129fbbf0e291a6e0487d5 accelerate
-
-# Once the release is out, this is enough:
-# python -m pip install diffusers git+https://huggingface.co/nvidia/RFD4-Proteina-prep@c9959efdebd75ac7fe9129fbbf0e291a6e0487d5
+python -m pip install huggingface_hub
+hf download nvidia/RFD4-Proteina-prep \
+  --revision c9959efdebd75ac7fe9129fbbf0e291a6e0487d5 \
+  --local-dir rfd4-prep
+python -m pip install ./rfd4-prep
+python -m pip install git+https://github.com/huggingface/diffusers accelerate
+
+# Once the release is out, replace the final command above with:
+# python -m pip install diffusers accelerate
 ```
 
 If using alternative installers, use `uv>=0.13.4` or `pixi>=0.82.1` before downloads.