Hi @milodino,
A warm welcome to the Bunnings Workshop community, it is fantastic to have you with us.
I'd suggest you grab a Kango 100mm Stainless Joint Knife, a bucket of Less Mess Multi-Purpose Joint Compound and a sanding sponge.
Give the patch a quick sand to start with to remove any loose material.
Next, give the multi-purpose compound a good mix, then apply it to the patch with your joint knife. Apply the compound and then angle your joint knife and pull it down over the compound to smooth it and remove any excess. You want it to be fairly smooth and level with the surrounding surface.
Allow the compound to dry, then sand it perfectly smooth with your sanding sponge. If need be, you can repeat the process of applying and then sanding a second time to get things perfect.
Once the patch is dry, prime and paint it to match the surrounding surface.
Let me know what you think, and if you have further questions, please don't hesitate to ask.
Jacob
