Do you mean sheetrock? If the damage isn’t too large an area you can cut
it out and replace with another piece of sheetrock. Then you tape, spackle, etc. If damage is really extensive pulling it down is your best choice and better left to a pro. Working above your head like that to such an extent is a terrible job.
If you're talking about not removing the sheetrock, that's not a good idea. There can be hidden damage that could compromise the integrity of the structure. You need to make sure that all of the damage is properly repaired and everything is dried out.
Plaster and compound mix together and spread were there is wholes spread even when dry sand smooth then paint