If you take tennis shoes to most shoe repair places with even the most basic problem, they tell you that they not fixable; you should throw them away and buy some new ones. For some shoes, that still the best policy, but it not the only option. Higher quality shoes are often repairable with a little time and extra effort.
In this Instructable, I be sharing with you the repairs I did to bring my Patagonia Huckleberry shoes back up to snuff. The heel lining was worn through in one of the shoes, so I walk you through replacing the other lining.
The lining is attached with a single straight line stitch in this pair of shoes. It is sewn onto the shoe inside out and flipped over the edge of the shoe for a hidden seam. Seams in contact with feet equals possible callouses and blisters.
Use a seam ripper or razor blade to tear out the old seam and remove the lining fabric. It will likely be attached with some sort of spray adhesive to several layers of foam. You will need to pry up the sub footbed of the shoe (correct term?) and pull the tail of the fabric from the bottom of the shoe.