Selecting specific part inside a model/object

I am trying to import a model into UE4 and I imported this piece of a kitchen (from a strange angle!) and I was wondering if there was a way to select a specific piece of this unit? How would I go if I wanted to change the thing I marked in blue, how to apply a material to that selection and not the rest that share the same color (the orange)?

Sorry if this is a new question! Would be cool I could explode this unit or somehow move items within a group.

You can’t do that within UE4–static meshes need to be set before you export to UE4.