Some methods of removing paint from surfaces are much harsher to the material underneath than others. While chemical stripping tends to be easier than other paint removal methods, there is more risk to the original material involved so take when stripping paint from aluminium surfaces, such as window frames, doors and car bodywork.
Lay down cardboard with a few layers of newspaper underneath and around the area in which you will be using paint remover. This will help with clean up, and catch any dripping paint remover.
Put on chemical-resistant gloves. Nitrile gloves are made to resist heavy duty chemicals, so they are the safest bet. Latex is cheaper, but it is only made for light duty chemicals.
Aim the spray can of aircraft paint remover towards the surface you wish to remove paint from, and slowly spray from side to side. Don't get the chemical on anything besides metal, as it will likely damage other materials.
Let the remover set until the paint comes off. How long to leave the remover on depends on the paint, and how much of it there is. Light coats of paint may come off in a few hours, while heavy duty paint may take overnight.
Once the paint is loosened -- if it has not been removed -- use a paint scraper to scrape away loose paint.
Use a steel wool pad to go over any spots where paint may still be stuck, or that are difficult to scrape with the scraper.
Wash the material and area with a garden hose. Wash any area where paint remover might be, including any tools used.
Make sure that the paint remover you buy either says "aircraft paint remover" or that it's safe for aluminium somewhere on the can. Many chemical strippers will eat aluminium.
Keep children and animals away from the work site. Paint remover is caustic and will cause chemical burns.
Always wear gloves when working with paint remover.