How do i get rid of mold on ceiling?

That doesn't look like anything can be addressed without removing the material it is growing on. Is that drywall the mold is growing on? You have to be very careful with mold and should wear a mask and gloves, etc.

First, make sure the leak, or leaks are no longer active. Then, depending on the amount of decay in the material, either paint, or cut out the damaged pieces and repair them. If the area where the leak was is nothing more than staining, you can paint over it with Kilz and then repaint the entire area to match if desired, or if you have remaining paint from a prior paint job, just touch the area up. If the damage is to the point of having rotted material, make sure that either wall studs, or ceiling joists aren't damaged to the point of needing replacement before dealing with replacing the wall or ceiling covering. Ie......sheetrock, wallboard, paneling, etc. Without question, make sure to wear the correct PPE to avoid breathing in the mold.

Ty appreciate the help

I agree with Michelle, mold is dangerous stuff. Even if the leak has stopped, that area needs to be opened up, cleaned with the appropriate cleaners and materials replaced. When that much mold has grown on and over surfaces to the extent shown, more likely than not you have the mold growing behind the walls/ceiling (which will spread across rafters and through the walls of the dwelling).When it is simply a surface mold on Sheetrock, you can prime and paint the wall and it will encapsulate the mold. This area (shown in the pic) is way past that.

Don't know the extent behind the walls yet appreciate thr help