If you didn't delete everything manually, you should find ipack in the programs list in control panel or ccleaner and just uninstall it. The ipack patching always backs up your system files as they were before you patched them.
avast flagged reload icons gui.exe reading win32:evo-gen virus, is it truly safe to flag as false positive ? i never used ipack before but dont see the gain from a win customization tool being virus ridden
yeah I am pretty sure it is safe. I myself am using it aswell as neiio, no issues here. It really just replaces icons and nothing else. You can also revert to default any time with the other exe files (it always makes backup of the DLLs). If you still don't trust iPack you can download ico files aswell.