Is there a way to repair ripped off fan connectors?

Go get a replacement cable and/or fan, as it's probably easiest.

If you are determined to try and fix it, you can try what I'll outline below. Just keep in mind these are tiny bits and they were not meant to be repaired, so it's easy to wreck these bits and tabs, etc. while taking it apart. Be VREY careful, and pay attention to how it's put together as you take it apart (tab orientations, etc.), so you can reassemble it. :)

• Use an X-acto knife with a fine point on it to gently pry the white plastic tabs back, while gently pulling/tugging the wire, to release the individual metal ends from the plastic housing.
• Carefully pry those metal end connectors open to release the wire crimped into it.
• Repeat for each wire.
• You should now have 4 metal ends separated from the wires (and the broken end bits of wire).
• Cut all four wires coming from the cable to the same length.
• Strip the insulation on each wire back about 3-4mm.
• Insert a wire into an end, and press it back together, and hopefully ther'e enough bite left on the metal end to grab the wire (use a very small bit of solider if help is needed to secure the wire to the metal ends).
• Insert newly reattached metal connector end back into plastic housing. If you didn't wreck the white tabs when taking it apart, they should slide in and "click" pas the tab, locking them back in the plastic housing.
• Repeat for remaining wires.