[V]

Its not hard at all and and everyone that knows a thing or two will tell you its all about the prep work prior to actually painting. Rattle can paint would work fine, ideally you would use a type for plastic(will flex some) and a good primer. Also sand down(if its the smooth look your going for) and then clean it thoroughly by using a prep-sol product that removes oil grease wax etc. and wipe it down good with a lint free rag or towel. Then paint it in light coats and keep the can moving side to side. Don't push down to spray if the can isn't in motion, you'll avoid drips and runs that way. That's a basic explanation for the average at-home person.

Oh and the aluminum pipe(I'm guessing its that) you'll want to scuff it up so the paint will adhere, Id suggest around 220-320 grit sandpaper