Hi Bob,
I have done this recently so here goes.....
Remove all records and unplug and take out carriage. If possible lock the glass lid. Then make sure you have enuf room to tip the jukebox on its back (you may need a hand as it HEAVY!!). At the base where the wheels are. Remove all screws and the base should drop out. Now you have some access to bass speakers but there are more screws inside to undo and get full access to the main grille and mouldings etc. Once this done the grille and mouldings easily comes off the front. Measure old speakers and replace with new speakers....
NUTTYSTEVE
December 2012