if you mean getting rid of phage Here are some steps for this in this link

bitesizebio.com/9014/got-phage-heres-how-to-get-rid-of-it/

with best wishes

http://elte.prompt.hu/sites/default/files/tananyagok/IntroductionToPracticalBiochemistry

It would help to have more information.  Are you talking about phage particles contaminating your DNA, or the phage DNA itself? What phage? How big is your plasmid?

What scale are you working on?  If you only need a small amount of plasmid, running your sample on an agarose gel and purifying the correct band (I've usually used Qiagen kits, but I'm sure there are other methods and products) will work.

If you need to purify larger amounts, it will depend on the relative characteristics of the plasmid and phage (or phage DNA).

http://elte.prompt.hu/sites/default/files/tananyagok/IntroductionToPracticalBiochemistry