The body of your shredder is likely thin. Notice hos the OEM lift pins are on brackets attached to the angle iron frame. Normally boxing in the pin like the photos others posted is best but in your scenario I think the outer bracket would just be going down to sheet metal and wouldn’t do much good. If it were mine I would get some 3” heavy wall square using and weld 6” long or so pieces vertically on each side of the frame where the pins are now and then bolt the pins to the tubing. If you didn’t have a welder you could even drill and bolt the tubing to the frame.