Water damaged EF-70-200 4.0 L USM

Hello,

My nice lens had an unfortunate encounter with a lake. While the camera was around my neck, the end got dipped in the water. Droplets made it inside and have left watermarks inside on the lens.

Canon says it is "beyond economical repair." Before I toss it in the trash, I'd thought I'd investigate alternate possibilities. Could I take it apart myself? Could the parts have value to anyone? I suspect that the USM is fine, just the lens needs an internal cleaning. I hate to say goodbye to my favorite lens.

Thanks for any ideas.

Jim