Hi Sybil,
Don't worry it is easy : )
Just wait for the pods to dry/turn brown. Little holes around the bottom of the cap part will appear. When that happens, cut the pod off and turn it upside down over a bag. Shake the pod and lots of tiny seeds will come out. Then you can just remove the plants because they are done, and as you probably know, will just turn completely brown and not look very attractive.
Remy