Hello there!! I was at one of the deaf crop a while back where some of the customers were telling me that they were struggling to open the inkpads at home. I found this tip a few months ago prior to the conversation about how to make it easier for people who have difficulty in opening the inkpad.
You just need a filing tool (BTW, metal works the best). It’s VERY self-explanatory in those photo. HOWEVER, I will strongly do a little at time because if you file off TOO much; the inkpad will NOT stay close if it’s been thrown or dropped. The tab is there for a reason to keep the inkpad snugly closed. If that tab is filed off too much OR broken off by accident or by force; inkpad will not stay close and it will eventually dry out.
So please be careful with those as the only way to correct that is either put rubber band on it OR purchase a new one.
I used the Finishing Files from CTMH, which is unfortunately no longer available. I love this tool!!
Like I said, those photos are very self-explanatory.