replaceing a dvd burner

i have a HP pc and i ripped the tray off my dvd burner. how easy are they to replace? how do i know the mounts will line if i buy a replacement? antd whats a good replacement i really only use it to burn dvds i dont ever use the dual layer either

 

If it's a laptop, get an external burner that plugs into the USB port.
If it's a tower, they're a standard size and will fit ok.
I use LG - Samsung and Pioneer are good brands too.

 

whats the difference between those two? and how do i find out what mine is?

 

i plan on ordering it from newegg

 

Is it a tower or a laptop? what it the model number?

Or

remove the drive to find a part/serial/model number, search newegg for that number.