You can do a phenol chloroform purification if it's a large amount. Here's a basic protocol. https://openwetware.org/wiki/Phenol/chloroform_extraction

Just be careful, phenol will give you a chemical burn if it touches your skin.

The are many ways to reduce protein content in DNA extract. For exemple, you can improve purity and quality of your DNA by using salts like precipitation with sodium acetate and potassium acetate. SDS treatment can also increase significantly the quantity of DNA. Of course, you can also check DNA purity by calculating A260/A280 ratio.