How do I paint the 86 grill black?
I don't know about the actually removal of the grill, but I have painted plenty of parts on my 87 with just regular old spray paint (but I am white trash, so this may not be your solution). I clean the surface, paint it with several coats of spray paint (letting it dry each time).
If you can, try removing the parts before you paint them. I have taken of and painted plenty of parts, but one part I could not get off before I painted it was the rear trunk trim. I had to paint it on the car, and even though I was real careful to tape and cover everything up, some overspray did get on the car. I had to use 3M Finesse-It II finishing compound to buff it out.
Good luck.
I'll assume, you want to paint the grill to look like the 87 grill. If you going for that look, the grills in 87 were different than previous years, the bars in them are farther apart.
Save yourself the time and effort of painting and buy a roll of black out tape, tape up the chrome and go, no disassembly required.
prep the plastic also get all the oils off of it so that the paint sticks
The paint that you are looking for is called SEM OEM trim Black. you should be able to find it in any parts store in a spray can. This is a satin finish that should match the rest of the satin pieces on your car perfectly. It is also a good idea to paint the headlight bezels as well so that everything is the same colour.