Bob, probably the easiest method, and the one that has served me for 5k plus miles is to drill a couple of holes roughly where the lip would be in the original plastic tubes. You then slip a tie wrap through holes and keep it loose. From inside the airbox you will be able to slip the clip over the tie wrap and pull tight. that gets the position. after this undo clips, pull tie wrap a couple of clicks tighter and next time you put clip on it should pull up snug as a bug. Good thing about this is that tie wraps are dead cheap so you don't have to get tension right first time. get it too tight and you try again.
Take care drilling holes though. what I did was flip clip over so that it lay inside air tube in the right place then drew round the end with a felt tip. i then drilled holes about 25mm further apart and about 10 - 15 mm deeper into the air tube.
Take your time and look at the job before getting stuck in with the drill. If needs be, drill the underside ones first, then if you get it wrong you can always re-drill them.
Hope this helps.....
