8BitDo Ultimate 2.4g- How to replace conductive rubber under triggers.

The Right trigger button on my 8BitDo Ultimate 2.4g Wireless Controller has stopped responding correctly 8 months after purchase. Support is sending me replacements for the conductive rubber located under the trigger buttons, but it may not have instructions on how to actually perform the replacement.

Could someone point me to a guide on how to do this? Apparently this is a common problem.

Any info appreciated. Thanks!