Removing a toenail should only be done by a medical professional.
Go to a doctor
I wouldn't recommend doing this yourself. In many cases, it isn't even necessary. Try soaking your feet in a solution of vinegar and water twice a day for 6 weeks. It will change the ph of your toenails and eventually starve the fungus to death. For more information see Toenail Fungus Cures.
As what others have already suggested, visit your doctor and let him/her do the job for you. This way you can be sure that your nails will not acquire infection. However, if you think that this is not an option for you, try to make apple cider vinegar solution and use it as a foot soak. This will help soften and lift the infected nail from the nail bed. There are also over the counter treatments that you can purchase to achieve the same result. One of which is zerofungus.