In the past, I have taken radios apart and "modified" them so that they would transmit and receive on the bands that I was allowed to operate on by the hang gliding association. I studied and passed a brief test and even carried a shrunk down license that proved I could transmit on the particular bands that we were allowed to. Taking apart the radio was always a daunting task. It was like surgery, which I have worked in for many years. Prepare a place to work, have the particular set of tools you anticipate and follow the recipe for the modification.
That's what I did today, no modifying, just cleaning and replacing, tightening and making sure my radio was in good shape, it is.
I bought my Kenwood TH-D72 used. The guy who sold it to me said it wasn't used much. He did not tell the truth. Needless to say I asked him to return my money, he sent back a $100 which made the deal ok. The key pad was worn and the radio was just dirty. I cleaned and polished the window, ordered new parts for it and today I replaced the keypad. I followed the suggestions of others that worked on theirs and after 2 hours of trying to reassemble, I figured I would just take it to HRO, it would not go back together. Hours of trying, it was just bound and I didn't want to break the case.
One last try...
Instead of placing the keys in the housing, I seated them on the radio insert and fit the housing back on and in less than 30 seconds, the housing was back in place, every button working, the radio shiny and ready for more.
Sometimes you just have to be patient and try things a little different.