Mazdaspeed as in Mazda Motorsports Development? It's been a while since I installed mine (on a NA) but I recall it was just a pair of bolts threaded into captive nuts and a couple of nuts on studs affixed to the chassis. I don't think it's any different on NB. Loosen and remove the fasteners and the old tow hook will come out. Put the new tow hook in its place and reinstall the original hardware. The hardware isn't welded. If you are having trouble try a penetrating lubricant like Kroil. According to Brian Goodwin, you might need to clearance some plastic trim underneath the bumper cover for fitment of the rear hook on the NB.