Remove all cushions, plastic parts and accessories before you decide to start painting.
Take the furniture to a safe area where paint spills will not damage the surroundings. If this is not possible, cover the ground with a large piece of plastic and place the furniture on top of it.
Wash the aluminum carefully using a metal sponge and mild detergent. This will remove debris, loosen paint and overcoating and make the surface smooth enough to accept the paint without bubbling.
Wash the furniture again with detergent and use a brush to remove any loose paint.
Paint the aluminum furniture with either a brush or spray paint. For small pieces of furniture, spray paint makes more sense, as it will get into creases and corners evenly, without bubbling up and missing any areas. Large pieces, including tabletops and chairs, can be painted with brushes and paint.
Let the paint dry before applying a second coat. This is especially important if you removed a lot of paint or if the base color is too dark and there is a chance it will show through the new paint.
Dry the furniture in an area that is protected from rain and strong winds. Such conditions can make flying debris stick to the wet paint.