Fill/Remove the gap/seam on surface in .step file

[yg_sunshine]

Hi all, I am given a .step file of a plastic part and want to simplify it for 3D printing and also for converting into polygon mesh (.obj file). The part has some nice details to show small screw holes and gaps where two parts assemble together (think the two halves of a plastic Easter egg, is it called flange seam?). I would like to get rid of the holes and seams so it looks like a whole smooth piece, please see the attached image for the "before" and "after". I know if there were a timeline one can suppress the "hole" feature, or modify the fillet or chamfer, but since what I have is a .step file, there is no time line or sketch to work with. So, is it still possible to fill the gap to make it smooth? Thanks!

Edit: Attached MC_03.f3d file

[davebYYPCU]

All things equal, import the file, edit the Base Model, 

Select the faces chain that you want deleted and Delete them.

Means the walls and fillets in the screw relief tube, 

Select the fillets and channel faces, as a separate operation.

Might help...

[TheCADWhisperer]

@yg_sunshine 

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply if you can't figure out @davebYYPCU technique?

[yg_sunshine]

Attached, please help to take a look! Thanks!

[yg_sunshine]

Thanks! But I don't see a faces chain as this was originally done by other party in SolidWorks, I only got the final result as a .step file. 

[johnsonshiue]

Hi! Is this result what you are looking for?

Many thanks!

[yg_sunshine]

Yes, this is exactly what I want! Thanks! Can you please share how did you do it? I see from the timeline there are DeleteFace1, DeleteFace2, etc., but still don't know how could I do it. I have multiple of similar structures need to be modified, so please teach me the steps! 

[davebYYPCU · Accepted solution]

Exactly what I said, select a set of faces (chained) together, in the region you want deleted.

Delete Face 1, right click the icon, select Edit Feature, it will show you what was selected (4 faces) and removed.

Might help...

[yg_sunshine]

Ah I see! My problem was I didn't select all chained faces, so trying delete will result in failure. Now I can do it! Thanks!