Toshiba PDR-M5 - cleaning the lense

Hello.
The outside lens on my Toshiba PDR-M5 lense apparently has a problem, because nearly all photos I take are blurred in parts. When I look at it close up, you can see a rectangle within the outside circular shape, and part of this appears blue and parts clear, with scratch lines into the blue parts. Cleaning the lense doesn't change this. I presume what is needed (at this point, which is now too late), is to get the lense adapter part and put on a lens cover to protect this to prevent this kind of damage. Now I need to know if there is someway to correct this, can I get a new part and replace this glass plate? Is this difficult to do oneself? I don't see how to open it from the front. Are parts available? Could a generic camera shop do this or would I need to send it to Toshiba?
I appreciate your help in this matter.
Ysteban