Disconnecting the fuel rail under the bonnet and then turning the ignition on will work fine.
Your only problem will be safely attaching a hose or something to the fuel pipe so you don't spill/spray fuel all over your engine as it's pumped through the fuel line!
Your only problem will be safely attaching a hose or something to the fuel pipe so you don't spill/spray fuel all over your engine as it's pumped through the fuel line!