As you are running on-premise your options are very much limited. There are a number of options on SaaS, but these are not available to you.
As mentioned by @henrikalmen an upgrade would be a very good idea.
The other option available to you is to hack the extension you have. If you open the extension zip file you will find that the contents are all plain text files. You can find where the word "Reload" appears and replace it with whatever text you need. If you know a little CSS you will also be able to modify the styling of the button.
Once done, just zip everything back up and re-upload the extension to your server.
