Several parts (particularly Chest.stl) have very minimal contact with the build plate. If you don't have... very good adhesion, add a brim.
Two chest options
Chest.stl This perfectly round part is the best choice if adding a scarf. The uninterrupted surface will allow the scarf to twist around freely.
Chest_with_Arm_Holes.stl Use this option if you plan to add posable pipe cleaner (chenille stem) arms.
Two neck accessory options
Scarf.stl - A long scarf that runs along the side of the snowman.
Sweater_Collar.stl - A rough textured ring that, when coupled with chest part with the same color, looks like a sweater.
Add buttons if desired. Buttons may block the scarf from rotating.
The main body of the snowman is held together by a rubber band, hair band, round or thin sewing elastic, or any other thin flexible item that can span between the head and the bottom and tie into a knot.
Print Head.stl & Bottom.stl or Head_with_Larger_Holes.stl & Bottom_with_Larger_Holes.stl depending on what you choose to hold the parts together. Hairbands and thicker rubber o-rings will require the "Larger Hole" versions.
The top hat is glued on. I recommend using hot glue, so you can remove it in the future.
See the video above for a step-by-step demonstration of the process.