I'm trying update a NX3610 to DellFluidFS-2.0.7680-SP in order to get to DellFluidFS-3.0.940120-SP-NX  but I'm getting the following error:

Service pack validation failed: Service Pack installation failed: Insufficient space 0MB in /var/lib/pgsql (needed 10MB), please contact support.

I cannot seem to find a way to access the OS shell. When I SSH I just get the FluidFS menu.

What's the trick to clear space in the /var/log/pgsql directory?