I'm 3D-printing a model of a 4-door jeep. The company that created the *.stl files included supports for some parts that are hard to remove. I had to use a jig saw to cut support off a part. To remove supports from parts, I used Fusion 360 but I had problems with supports on two parts and I used 3D Studio MAX to edit the parts. Fusion 360 doesn't let me select a face because the selection brush selects extra faces. When I export parts to *.stl files and import them into Simplify3D software, the parts come in 10 times bigger and I had to scale them to correct scale. How can I fix the problem?