[doc] Update CUDA installation instrucctions

doc/install.rst

@@ -52,18 +52,22 @@ Choose the relevant tab for details on each of those installation paths.
 
 .. tab:: CUDA
 
-   Checkout the repository on a **CUDA-enabled machine**, then use pixi_ to
-   create a mixed deployment and development environment for the checkout:
+   Checkout the repository, and then use pixi_ to setup a version of this
+   package that can run on a CUDA-enabled machine:
 
    .. code:: sh
 
       git clone git@gitlab.idiap.ch:biosignal/software/mednet
-      rm -rf .pixi pixi.lock  # clean-up any previous CPU-only install
-      ln -s helpers/cuda/pixi.toml .
-      ln -s helpers/cuda/pixi.lock .
+      cd helpers/cuda
       pixi install --frozen
       pixi run mednet info
 
+   .. tip::
+
+      The ``--frozen`` flag will ensure that the latest lock-file available
+      with sources is used.  If you'd like to update the lock-file to the
+      latest set of compatible dependencies, remove that option.
+
 
 .. _mednet.setup: