To handle tough stains, clean the plastic with a mixture . 5  fl oz (15 mL) of any liquid laundry detergent and 16  fl oz (470 mL) of warm water.

You can order conditioner online. You may also be able to find it at home improvement or auto parts stores. Plastic restoration kits are also available. They usually include conditioner as well as applicator pads.

If you are worried about discoloring the plastic further, test the conditioner in an inconspicuous spot.

Be sure to read the manufacturer’s instructions on the product to check the drying time and any other special instructions.

Follow the manufacturer’s instructions for repeated applications. Over time, this may improve the plastic. If the conditioner pooled and appeared to have no effect, repeated applications probably will not be enough to restore the plastic.

Buffing products have varying strengths. Some are designed for light scratches while other are effective on deeper cracks. Always wipe using circular motions. If you scrub the area, you will wear down the plastic.

If you get a non-spraying polish, lightly coat a microfiber cloth with the polish.

If you notice any excess polish pooling over the plastic, simply wipe it off with your cloth.

Wearing long-sleeved clothing can also help you avoid accidents.

If you are able, remove these components before treating the plastic. Make sure the tape is flat against the plastic, sealing off the area you wish to protect.

Hydrogen peroxide cream is like a gel, so it’s very easy to spread over the discoloration without damaging the rest of the item. The cream is used to color hair, so you can often find it in hair coloring kits or purchase it at hair salons.

The garbage bag has to be clear in order to let in the sunlight, or else the cream will dry without treating the sun damage on the plastic. Check to make sure the cream isn’t already drying out. Rinse it off and add more as needed so it doesn’t disfigure the plastic.

A table or a stone surface is a great place to stick your item. Make sure it won’t be disturbed there.

The sunlight and shadows may change throughout the day, so keep on your toes. Watch for any holes in the bag. If this happens, add more cream before the old layer dries, then move the package into a second bag.

Be careful if you’re cleaning off something delicate such as an electronic device. Avoid using too much water. Make sure the rag isn’t dripping wet.

When you’re finished, peel off any tape you used. You can then apply a plastic polish if you want to make your plastic shine.

Give plastic a thorough washing before attempting to restore it. Plastic restoration products always work better on clean surfaces.

You can let the plastic dry in air, but more dust and debris will settle on it the longer you wait.

While you can get away with not sanding, roughing up the surface a little helps the paint stick to the plastic.

All-purpose cleaners are effective against oils, which can settle on exposed plastics such as cars. Another option is rubbing alcohol. Rubbing alcohol is very effective at removing leftover oils.

Painter’s tape is designed for this purpose, but using other varieties, such as masking tape, may also work. You can get painter’s tape from most hardware and home improvement stores.

Wearing long-sleeved clothes also helps protect your skin. Select old clothing you don’t mind discoloring.

For extra effect, apply a layer of primer first. This usually isn’t necessary, but it ensures the paint sticks to the plastic. You can also dyes, such as trim dyes for cars. Squeeze a few drops onto the plastic, then spread the dye with a foam brush. You can paint the item any color you would like, but you may wish to match the paint to the item’s existing color scheme. Always keep your hand moving while you paint—you don’t want one spot to get a more concentrated amount of paint.

You may also want to apply a paint sealer when you’re finished in order to preserve the paint job longer.