Hey, I painted the dash pieces on my previous Titan and it was fairly easy. Are you wanting to paint the entire dash or just the various pieces to break the overall grey?? If you want to paint the dash pieces you just pull them off, prime, paint and re-install. Some just use spray cans but I prefer using a normal autobody gun if available. The dash pieces are already smooth so it is very easy. Be careful taking off the instrument cluster piece as you will scratch the plastic above the key switch. If you are talking about painting the entire dash you will need to get you a can of plastic promoter, 80 grit sandpaper, a gallon of high build primer and whatever paint you want. Remove the dash from the truck (which will be a long job), HAND scuff the dash with the 80 grit paper or scotch brite and spray the heck out of the dash with the high build primer to "fill in" the texture. (Polyester primer will work great from you local body shop). Dont worry about runs as you will be sanding all of them out. After your primer has dried, sand the primer with 600 grit paper to smooth it off. The primer will fill in the texture and leave you with a smooth surface to paint. Also remember that a painted dash is hell on the eyes becasue of the glare from the clearcoat. Good luck on the project! Here is the link to my old titan.
My Titan, for the second time