St Martin's Church in Kensal Green sprang into action after schools and properties were evacuated on Thursday.
The bomb, weighing 500lb (227kg), was discovered by construction workers who were digging in in Brondesbury Park, Brent.
Experts from the Royal Engineers and Logistics Corps were then called in to create a blast protection layer around the device.
The structure had to be put in place before they could begin work to make the device safe to move.
The Army said: "The Army's Royal Engineer bomb disposal experts continue to work through the night with the emergency services and partner agencies in Brent where an unexploded German WW2 bomb was discovered yesterday.
"The soldiers are constructing a blast protection layer around the device before they can begin work on rendering it safe."
According to Brent Council, work on the site is expected to continue until at least Friday afternoon.