While I agree with the message you are trying to convey, the 2020 case doesn't have to be more complicated than the 2010 case:

2010 edit an html button:

0. Install an ftp client (you need to mention that if you mention installing git)

1. pull the file from ftp or sourcesafe/svn

2. edit the button

3. upload to ftp

2020 edit an html button:

1. clone the code 2. edit the html button 3. commit changes