I fitted one of these 2000 miles ago and fitted it the same way I've fitted loads of these type of things - mainly "fender extenders".
Bin the rivets, superglue either side of the sponge tape and press in place for a minute or so. I've never had one effected by speed, weather or washing, but you can still get them off when you need to. It will leave a small amount of superglue residue on the underside of the original guard but it's not visible and is better than drilling holes imo.
2018 Ducati Supersport S = Red
1998 Suzuki GSX-R 750 W = Blue & White
2003 Suzuki DRZ400 E = Yellow & White
2016 Yamaha PW50 = Black & Blue
2017 Honda CRF 50 = Red & White