The proper functioning of the operating buttons is critical for playing cassettes, pausing cassettes, recording sound, as well as fast forwarding and rewinding cassettes. All of these buttons can be replaced to restore functionality to the Sony TCM-919.
Turn the device around so that the back cover if facing upward. Use your thumbs to press firmly down and then push the battery door cover open.
Remove any batteries.
Remove the 5 5.95mm screws as indicated in the picture with the Phillips Head screwdriver.
Look to the back of the top cover and locate the broken button(s).
Use a splunger tool to undo the two clips that belong to any broken buttons.
Turn the device over and using your finger, push out the loose button.