I suggest you get Photoshop. Now with Eraser, alone, it'll get you nowhere. With Photoshop, it brings a tool called Magnetic Lasso. What it does is that it "grabs on" the image when you go by with the mouse.

When you have fully connected all the dots that "grabs on" to your image, you can put it on a blank, seperate page and edit anything that you don't like with the Erase tool.

i do have photoshop, and thx for the help, ill see if I can find that magnetic lasso...where is it????

To your left. It looks like.. a lasso.

its called lasso tool on my computer, is it the same as magnetic tool?

Yeah.

Yup i also use the magnetic laso tool to cut out my renders, otherwise i think it is quite hard to get a clean and smooth cut.

Since the questions have been answered, I'm gonna close this.

Locked.