I use a regular Waterpump plier.
The clamps are reusable and are easy to release and tighten when reusing them.
The technique is described in the rep DVD.
Even if BMW specifies a specific plier for this purpose, opening the gap on the WP plier enough to where the jaws stays perpendicular will offer a good enough grip to open the clamp, as it only takes 2mm movement for the clamp to release.