Easiest ever Mickey Mouse cake topper! :) 

19.

Check the length - they should reach or almost reach the cake dummy. 

20.

Let them dry for a few minutes. They need to get firmer. That way they won’t lose the shape when you cut them. Roll two 8 mm balls of white flower paste (gum paste). Let them dry for a while too. 

When all parts are quite firm, trim them as shown in the photo. Stick the hands to the arms. Use a very small amount of glue. That way the parts won’t slide around and the glue won’t ooze out. 

21.

Stick the arms to the body. The hands should reach the cake dummy and the arms should touch the side of the body. Trim the top part of the arms if there’s need (so that they don’t stick out above the flat surface of the neck).