To do it probably you'll need to take out all the guts from the enclosure, trying to paint with them in will be a nightmare.
I use Carplan acrylic paint cans, tried others and some are terrible, and don't harden quickly enough. Plastikote acrylic is really bad, takes months to harden off properly. Try to stay with the same manufacturer for each type, primer, colour, and clear, as there's no guarantee they will be compatible between manufacturers even if they are all acrylic.
I wouldn't paint over the existing finish, it's possible, but it might react as you've no idea what type of paint was used originally, and it might look OK at first, but in a few weeks it starts to wrinkle, and you are back to the start again.
Stripping the existing paint is fun(!!), and is probably the longest part of the process. An electric sander works well, but dont go to mad, so you dont get deep marks in the metal, which will need more sanding to remove. The surface needs "keying" for the paint to adhere, but no so deep as to be visible through a couple of coats.
I do a coat of primer, 2 or 3 coats of colour, and 4 or 5 coats of clear, and get a good finish. If the enclosure is bare metal, then 6 or 7 clear coats, and a slightly heavier "keying".
I lightly flat with 1000 grit paper after the colour coats, and after 2 clear, and again before the finish clear if necessary. Any decals go on before the clear coats.