Don't think any repair will be satisfactory. However, individual lengths of the siding may be removed & replaced. Be sure it's a warm day. Check with an installer and they should be able to show/describe how you can do it. Basically will have to release the section above the one you want to replace - carefully. Then rempve nails holding bottom piece and push downwards to release from the starter 'clip'. Replace bottom piece by pushing upwards to snap onto bottom 'clip' and nail without pounding nails in completely. Then, carefully, snap the upper piece over the top of the bottom one. Should work out fine.