Problem after upgrade to 2.0.15 - 2.1.0 local modifications

I am becoming cs cart addict :). Almost. Migrated from OpenCart. My first post. Hello world.

I have done a upgrade 2.0.15 - 2.1.0.

In manual and in other sources I read:

[QUOTE]There is a list of the files which were backed up during the upgrade and two links next to each file: Change and Mark as resolved[/QUOTE]

I don’t have and change link in Installed upgrades - The following files had local modifications:

I just have Mark as Resolved link. When clicking on it everything is green. No red code.

I have 5 files to resolve, all are skin related.

  1. How I start to resolve this things. Take Winmerge and start to compare files in which directories?

    /var/upgrade/upgrade_2.0.15-2.1.0.tgz directory backup and package?
  2. And after change replace it in main skin dir or elsewhere?