They come off easily with an X-Acto knife to get it started and then tweezers for removal. No heat required. Save them in case you want to revert to stock configuration. I'd be afraid of high heat damaging / melting the headphone.
The Bass Port Mod is tunable.
If too little bass in stock form and too much bass after removing the stock adhesive disk, try disks using double-sided tape with various hole diameters.
Art supply stores sell 3 x 3 foot sheets of double-sided "tape" material. It is not expensive. Its protective cover is stiffer than double-sided tape that comes on a roll. This makes it less prone to "self-sealing" if you leave the protective covering on one side in place. This is...
Gents, here they are...cCasper's Custom Painted BMF T50RP cups and slider rails with Alcantara Pads and Custom Balanced Cable....Sweet!
They look much better than my crappy iPhone pictures and, modified, they sound wonderful.