It's quite possible and quite easy to dismantle a VHS cassette and inspect the interior - you might try doing it on an unwanted scratch tape first just to see how the tape is wound - then, when you're confident simply take the important tape from its original casette box and drop it carefully into another box. You will need a small cross-point screwdriver and perhaps a pair of tweezers - keep greasy fingers away from the surface of the tape.
Good luck...
Peccavi, December 2009