Learn how to alter jeans and other denim pieces on http://AllFreeSewing.com
diy: how to take in jeans at the waist, denim skirts!
Genius, easy technique to preserve original hem. Straight-leg jeans with not-too-much to take off would work best & I'd finish the inside seam (after cutting) somehow to avoid fraying.
how to alter jeans for a perfect fit - center waist dart
Here's a simple sewing trick for Letting Out the Waistband in Jeans. This no-seam-ripper sewing alteration takes about 15 minutes. And, no sewing experience is necessary. Make your jeans comfortable in just a few minutes.
Learn how to take in a jeans waist - step by step tutorial