How can i DIY fix a dent in my rear bumper ? , I rather keep the check from the auto insurance b/c the dents not that terrible or life threatening and i wanna try and see if i can do it my self .

i am plotting to DIY because i am on a thight budget…
pls give the exact measures of the lenght, width and height of the enclose.
I am just a newbie in setting up car audio so pls. help me out.
any answers will be highly appeciated.
thanks in development.