Bumper guard/protector

Ok, so I tried in vain to fit one of these at the weekend. I've got one exactly like the attached photo to fit on, but no instructions. There's two 'U-clamps' to hold the guard onto the round beam behind the bumper, so I understand that bit ok.

Whats the deal with the four slotted holes? They seem to line up with tapped holes on the section that sits below the radiator. The only issue being they look like the underside of these tapped holes ie I can see the bottom of the bolts that are screwed into them.

Have I got to remove the radiator and install longer bolts into these holes? Or use big ass tie wraps onto the chassis somewhere?

cheers for now guys  

The 2 clamps would be enough to hold it, that’s all I used

Good man, cheers Whytie. I might be able to get it on tonight in that case

I think I was able to use one bolt into that section below the radiator. All the other holes were flogged out on mine.