Did you purchase the software or are you running a trial or demo?
Try "fillet" command. Saves a lot of time, the alternative is just as mentioned.
Does your CAD have any tutorials? Do you have a command line?
If you haven't paid for the CAD program, download RhinoCAD and go through the tutorials. The first is simple 2D and 3D, the second is a 3D solid and the last is a 3D "rubber ducky" made from solids streached using NURBS which is how you would make something non dimensional, like a rubber ducky...