Hi,
In this i like to say how to change a single movie clip to other...
Some time we might need to change a particular item in a movie clip we can do that with the option called swap.
It can be done in the way of.
Select the movie clip what you want to change.
Select the properties window(ctr +F3 to open the properties).
Click the button swap and select the movie clip to change.
It will get replaced.
Note : In the case of swap a movie clip inside another Movie clip it will affect all the place where that main movie clip is used movie clip.