you need to cut it away to clean metal, glue in a patch panel with panel glue, seal it with sealant, blend it with bondo, prime it, paint it.
in short, if you've not done much body work before you wont be able to make a lasting repair yourself. just bondo'ing it will make it worse.
in short, if you've not done much body work before you wont be able to make a lasting repair yourself. just bondo'ing it will make it worse.