i was given a .dxf file that was in metric form.  how do i convert this to imperial???

Hello,
 
Here what i would do:
Open the drawing, scale them use these conversion in Autocad:
 
if : m to feet   > 3.28083 (scale factor)
     m to inch   > 39.36996
     mm to inch > 0.03936996
 
hth, thanks.
Rman.