A little trick when you are installing an Ultratorque crank: Before you put the driveside crank into the bottom bracket cup, push the clip so that it is almost ready to slip into place, then push the drive side crank into the cup. Then all you have to do is to push the clip the last mm or so to where the ends of the clip snap into those tiny holes. After you have done it a few times, it is easy. It took me about 10 times before it became easy for me. A company other than Campagnolo, less focussed on appearance would have put that clip on the non drive side
I have installed dozens of Ultratorque cranks, so what seems easy for me may well seem difficult for someone who has only done a couple