OK, call me a sourpuss for saying it, but... while this is not the worst route in Eldo, it is certainly one of the least worthwhile.
To find this climb walk up to the south on the West Face of the Petit Bastille, you will pass a huge right-facing two-colored dihedral called (surprise) "Two Tone Dihedral" and not far to the right and above that you will see a bulge just off of the ground, above that is a short handcrack.
Climb the bulge to the right and then come back on secure incut face moves to reach a handcrack. Place bomber gear and climb up and through the second bulge. After this, the climbing is essentially over and you have 10 more meters of picking through trashy rock to reach the top. This can be accomplished by aiming to the right side of a short, right-facing dihedral up to, where there is a tree. A better option is to escape off the rock to the right. The best option of all is to just skip it. The handcrack is fun, but the rest is not even worth the effort of the 60 second walkoff.
A light rack with a few hand sized cams.