User:MZMcBride/stripredlinks

It's activated the same way any user script is activated: importScript('User:MZMcBride/stripredlinks.js'); in your relevant /skin.js subpage.

You should be able to read through the script fairly easily. It takes a list of pages and temporarily removes the red links. For example, if you have the following list:

• hello
• this page doesn't exist
• goodbye

This script adds a link to the sidebar ("Remove red links"). When you click this link, the list will read:

• hello
• goodbye

Until you next refresh the page (i.e., temporarily).