Good morning IDMT ,the most important thing is to match the paint ,you should be able to buy a rattle can already mixed especially as you state you have no spray gun as such .If it is textured and has damage you can also buy texture coat in a rattle can . Some have different grade cans some have just a different nozzle to give the effect .Another way to reproduce the exact texture is to use a piece of artist silly putty on a good piece of interior apply a little pressure and hey presto you have a mould for texturing .Just apply your mould over the textured area lightly and this will make the rattle can texture look the same as the original .Once dry if its a bit too obvious use a 2000 grade disc lightly knock the top back a touch .Now you can apply your top colour .If you use a waterbased item you may need a sealer over the top ,we used to use a silicone spray once dry . With the prep really just as Mitch has said previously but make sure you give it the degreaser as you will get bad effects if all polish residue is not removed . One last little trick that may work for you if its just a colour repair in standard plastic trim is to just gently heat the effected area with a hair dryer ,No i am not mad ,it appears that a lot of plastics will regain the original colour with the gentle application of heat .I hope some of this will help with your repair /project .