When it comes to getting a hole in the bottom of a gutter for a downspout, I’m sure the pros have some quick way to punch out the perfect hole in a few seconds, but for us home owners we are stuck doing it by hand.  Here is what worked for me.



Step 1 is to draw the shape of the hole and drill s few holes around that shape.




Here you can see the shape of the downspout flange I had.  This one came with holes in it for rivets.






Then I used a fine tooth metal cutting blade in my jig saw.





because of the shape of the gutter, you can’t get your saw down inside the gutter to make the cut so you will have to flip it over and cut from the bottom.   I put some duct tape on the bottom of my saw so I didn’t scratch up the bottom of the gutter.




After the hole was cut I slid the flange in to test the fit.





Here is the downspout flange from the bottom view.




I used SeamerMate to make it waterproof  and hold it together.




I didn’t have a rivet tool so I just used lots of  SeamerMate and it actually held up well.