I don't know if this is what you are looking for, but I was having problems in handling the dxf file with so much lines in it... maybe my computer is not as powerful as I thought...
I followed the instructions of this lpseifert guy here:http://www.eng-tips.com/viewthread.cfm?qid=156840
See the result in dwg format for AutoCAD 2010 attached.
Then I removed one of the layers that was causing the problems.
I drew each of the circles myself, so I lightened the drawing a bit (not the archs or curves).
Don't expect me to explain what I really did because I am not even remotely an expert in AutoCAD =)
I have done the dimensioning of almost every piece (in metric system), if anyone needs them, again for AutoCAD.