not a good way, but you could save the parts out as a parasolid, and bring it back into SW. now it has NO features. but you can run featureworks to attempt to re-create the features.
but you would probably have better luck just re-modeling it from the beginning, now that you know where you want to end up.
The only thing I can think of is that you could export to IGES or STEP, then import it and run the FeatureWorks wizard to try to build new features. I wouldn't recommend it though, because then you will lose all of your original sketches and nothing will be constrained anymore. Also sometimes it might not be able to recognize features successfully and other times it will end up making more features than it needs to and might be more complicated than your original.
In general when you are editing a part if you need a feature longer or shorter it would be better to change dimensions of the original feature rather than add a new cut or extrude. And if you want to fill holes it would be better to delete the holes rather than extrude to fill them in. That way the feature tree will stay concise and it is easier to make more changes down the road (because there aren't multiple features controlling the same thing).