YBR 125 getting the covers off the speedo ???

Hi

Have an annoying wierd problem that the plastic covers on the speedo and rev counter seem to be smeared as though someone has tried to clean the inside of them badly !!!!

Now when i try to pull the covers off the clocks they feel as though they would pop off with a bit of encouragement, is the only way to get the covers off to break them off carefully then re glue them down afterwards ?

Thanks for any help