The above link has a good picture of Motocycho's great idea and method.
When I did mine, I tried to do the cutting as square as possible.
Then I filed a bit to get the ends square, as well as the ends of the cutout section.
I coated all of the internal tube sections with grease, reassembled with the cut out section added back in, plus a "gap spacer", while the pivot bolt was being inserted.
Re the "gap spacer", I found a washer of suitable OD X ID x a thickness nominally the same as the hacksaw and filing work was.
My intent was to better protect the pivot pin, and prevent as much as possible any rusting over time.
Otherwise, crap, muck an mire is going to easily get into the tube/pivot pin gap.
Like my auto shop teacher taught us: "pretend you'll be the guy that has to take it apart next time, and next time could be a long time".