Heres the foams youll need.
http://www.wooferrepair.com/advent.html Very easy job, but a bit tedious.
1) Use your fingers to break away and tear off as much as the old foam as possible.
2) Take some acetone to the woofer baskets and remove the old glue. I use a popsicle stick to get the glue removal started, then you can roll it with your thumb.
3) Lightly sand the cone to remove old foam and glue residue. It doesnt need to be perfect, but the more you remove, the merrier.
4) Apply a bead of glue around the edge of the cone and attach new foam. Let sit for ~1 hour.
5) Apply a bead of glue to the woofer frame and attach foam.
6) Lightly exercise the cone back and forth, make sure you press in from around the dustcap. This centers the voice coil in the magnet. Repeat this process every 10 minutes a couple of times.
7) Enjoy your new speakers. The woofer foams may take a few weeks to break in. When they do, the bass will dig deeper, as the foam has stretched to match the excursion of the woofer.