Reducing mesh faces to create a solid

[gbeniaris]

Good evening,

The picture I'm sharing with you all is a fingertip. Its part of an armor set that I intend to 3D print. If you look at it, you'll see that it has over 10,000 triangles and other assorted shapes. This does not work for me.  There's already an insert where the finger goes. I just need to convert it to a solid. Easier said than done. Converting to a mesh gave me something that is... not that. I need a way to combine these faces to make turning it into a solid a little easier. Any ideas are welcome. 

[jhackney1972]

Can you please attach the Mesh File (stl)?