How badly stained/dirty is it?
For our 21TD03 Recall for the Tacoma 3rd Brake Lamps, Toyota specifically wants us to use either ZEP Foaming Glass Cleaner or Toyota Genuine
Glass Cleaner with a micro fiber cloth to attempt to remove staining from the headliners.
I didn't think it would work that great, but I have a can of the Toyota stuff and it works really well for cleaning up a headliner if I accidentally get a spot of grime on it or if I am helping a customer out.
Here's a section from the technical instructions detailing how to clean the staining out of the headliners.