In order to save me from writing the history of the universe out, here's a link to the procedure -

https://www.doityourself.com/stry/ho...uel-pump-relay

Using a multimeter on the pump is pretty straightforward. Unplug the connection to the pump, set the meter to check for continuity/resistance (whichever is easiest for you). If you don't get a reading out of it, check you're making good contact to the terminals on the pump and try again. No reading = pump has failed (open circuit - there's a break in the internal windings somewhere)