You cut off the long side. The "C" is welded to the tube only on the outside. Before I cut it off I use a 4 inch grinder and cut the weld as close to the c as possible. You hold the grinder perpendicular to the tube. I used to use a lathe but that weld is pretty hard. And rough on the cutter. Then after you cut it off I drill 4 holes into the tube straight down from the outside of the C . The I use a sawsall or die grinder to cut almost to the C. Then you can usually just knock the tube out of the C. As long as most of the weld between the tube and C is gone! Then clean up the tube with a fine or mostly wore out 4 inch flapper face on the grinder. You just want the crust removed. Heat the C with a weed burner. Don't turn it red hot. I use an infrared temp reader. If I am showing someone. About 400 degrees works well. Then the C will slip on the tube. Adjust the angle. I should add I have a jig made up to hold the housing, it holds the face of the pumpkin perfectly level vertically. That way when I use my angle finder. I know it's set correctly. Then 4 tack welds. Double check the angle!! Then weld it up. Also. I usually send a few axles at a time to get shortened. They only charge a little more for 2. Than one. Part of the cost is setup. That way i have spares.