Dump the crushed pineapple (juice and all) into bottom of pan; make sure it is evenly spread on bottom.
Dump the cherry pie filling on top of the pineapple; make sure it is evenly spread on top.
Dump the dry cake mix over the top, spreading evenly across the top.
Melt the margarine in microwave (or stove top if you prefer).
Using a large serving spoon, evenly put melted margarine over top of dry cake mix, making sure it goes clear to the edge and the dry cake mix is covered. (You may not have to use all of the margarine. I just melt that much so that I will have extra in case I have trouble spreading it).
Bake for 60 minutes at 350 degrees Fahrenheit.
Check it often toward the end of cooking because it should only be golden brown and it is easy to get it too brown.