Manually winding a loop of tape back into the cassette
When you extract a tape from an uncooperative VCR, there is likely to be a loop of tape dangling in mid-air. Where the tape tape hasn't been seriously crinkled, mashed, torn, or otherwise damaged, it may be possible to get it back into the cassette with low risk of further problems.
WARNING: If the loop of tape is badly crinkled, mashed, at all torn, or damaged in any other way such that it could catch the spinning video heads, throw it away. If you must save the material, see the section: Recovering damaged or broken tapes.
There is a hole in the bottom of the cassette about 1/4" in diameter in the middle approximately 1 inch from the label side (front). Depress this with a suitable tool (a pencil will usually suffice), and the reels will be free to turn. Carefully wind the tape back into the cassette. That's it!
above is from the site http://www.repairfaq.org/sam/vcrfaq.htm
sd, December 2005