Cathy
The pods must be left on the plant. Harvest when they turn brown (can take a few months). They will feel soft, almost mushy. You will be able to feel the seeds inside. Generally, ripe seeds will be brown.

Here are some pics:

ripe pod

seeds

The seeds look like brown shriveled up things. The actual seed is inside the shriveled looking coating. You can soak them overnight, then peel away the seedcoat to reval the seed, which looks like a tiny bean.

Hope this helps a little.

~mamabirrd

The same thing happened with mine. All of my other datura plants pods had split outside and the plants died off on their own. One didn't and had 3 pods, so I brought it inside. The first two pods had shriveled somewhat and the seeds were moldy. The last remaining pod is getting larger and is nice and shiny, so I'm hoping that one will produce some viable seed. I had promised these seeds to someone, thinking they would split back in August, but it's been taking a long time, alot longer than usual. But, they are supposed to split on the plant. I haven't opened any pods before their time. Maybe when their dried sufficiently you can do a test planting inside and see if they germinate.

I was told by a man that own a nursey that as long as the pods have quit growing you can take them off and let them dry out. and as far as these big pods go you can cut the pod open so that they can get air and dry out without molding. We shall see.
Thanks for the help
Momma bird my pods dont look like that they are big and round about the size of a golf ball.

Cathy, you have Datura. When you said Angel's trumpet, I assumed you had Brugmansia. Sorry, my pics are from a Brug seed-pod. ~mamabirrd