Before you attempt to replace you should contact a Professional Plumber.
Be cautions when attempting to fix!
Be cautious when attempting to tighten the faucet/packing nut of the bib. If the internal pipe the hose bib is attached too is not copper or other rigid material, it could crack. More modern homes have CPVC piping installed within walls, and twisting the pipe may cause cracks which can lead to water leaking within the wall. This can cause severe damage as an internal leak is very hard to detect until the damage starts.