I am trying to change the name of the tab that appears in the ribbon of Excel 2016 of a custom addin (xlam file) that was created before me. I found a stack overflow answer (How do you rename the tab of a add-in in Excel when customizing does not work?) that said to unzip the xlam file and I was able to edit the xml file that contained the tab name in the unzipped results (in the customui directory). Now I am trying to reassemble the xlam file but I don’t know how.

I tried adding the unzipped files and directories to archive using 7zip but the resulting file was recognized as potentially corrupted and did not work at all. How do I reassemble it?