The "Magic Tracks" in that kit were designed to snap together, but they won't hold together long using that method. I remember forming short lengths of track to curve around the idler wheel and drive sprockets using Tamiya extra thin cement to bond things together, but with the long runs on the top and bottom, I used standard Testor's liquid cement. Allow it to sit for around 15 minutes to firm up, but remain flexible enough to form properly over the road wheels. With particularly stubborn links, just a touch of cement can be used to re-soften the bond to allow you to reposition the link a bit.