Can someone help me replace my ear pads?

I have this exact model but after quite a bit of use the earpads began to tear off, i got new ones and fully removed the half torn pads that i had but now i can't seem to put the new pads in. I tried using the little dent in the case of the speekers but it wouldn't help, i tried streching the pads and putting them on the headphone but it didn't work either. any ideas? or am i missing something?