You can edit the settings page to change it.

This is my naughty blog right now. Notice how the icon is that snazzy default thing?

That’s because it’s set to explicit, a setting that was locked after the great purge:

BUT

If you right-click on that toggle and click “inspect element”, you can change that.

Notice how the input tag has a disabled attribute? Just remove that whole thing:

The toggle is now active

And toggleable

And now, after a quick refresh, my old (crap, but real) icon and header image are back, and the blog is no longer treated as hidden or explicit.

The goggle also disappears after the refresh, but it’s worth noting that you can also edit the toggle back into the settings panel and change your blog back to explicit if you so desire.

This is a perfect example of the laziness of tumblr’s devs. They haven’t removed the functionality, they’ve just kinda-sorta hidden it a bit; the end-point that the explicit toggle hits is still there.