I found that the old ring can be dislodged fairly easily with a thin flat blade screwdriver. Try it both from the top and under the bottom through the torn diaphragm.
The new ring should be warmed before installing it, to make it somewhat pliable.
The official way to do this, I don't know. I boiled mine for 5 minutes. Installation was several weeks apart. The first one was no problem. On the second one, a little bit of the 'inside' edge (the small-diameter edge) of the diaphragm kept sneaking out of place during the final 'snap' of the ring... It took me 3 tries - but I just did a 400 mile round-trip this last weekend, and I totally forgot to worry about it!
The hardest part, I found, was lining up the index tab on the 'inside' edge (very important) and making sure it stayed in place during ring installation.
I would call the guy at Bing for hopefully a real answer on heating them.