Don't worry I am a gunsmith student and I will help you!
We saw in our cours how to solve the prob.
But first never shoot old ammo if possible,
And always keep your ammo in a dry place.
If the bullet didn't go out its probably because the powder was to humid
and the bullet didn't have enough power during the detonation to pass the rifling which is smaller than the barrel diameter. With the time the powder absorb humidity and than it become neutralize. So if you shoot with old ammo sometime you can have enough dry powder to detonate but your balistic's gonna be wrong cause only a part of the correct amount of powder burned so the speed of the bullet is affected.
to take off the bullet, you need WD-40, a hammer and a long punch or a long small metal tube strong enough to take hammer shot.
First you take off the barrel of the slide and you put it into a vice.
Than you put WD-40 generously inside the barrel.
You take the long punch and you hammer it until the bullet come out.
Don't be shy to hammer it!
If it don't work you better looking for a gunsmith for sure but in 80% it work.
When the bullet is out lub the inside again and take a cleaning kit with a brass brush and put some decopper on it and brush the inside carefully.
Pass a dry cotton piece inside the barrel.
If the color of the cotton is green a little, Do the same operation one more time. When the cotton stay white, its because your cleaning is good.
Finally make sure the rifling is not too damaged and good luck with your gun.