@Mackeral_Fillet I was told by @Chris D that editing the phrase nav.home was the best way about going about it. For me it was nav.forums as I was trying to replace the forum text with home text.
Anyways that's definitely the right way about going about it. I remember home was also greyed out for me as well.
You probably have debug mode enabled, or it could be a custom navigation entry (not assigned to an add-on). If it's the former and you have debug mode enabled, In editing directly, you are changing the master version of the phrase. That change will be wiped out when you next upgrade the add-on (or XF) the entry belongs to.