How do I delete multiple contacts from IPhone 5S at one time ?

I have a new I phone 5S how can I delete multiple contacts at one time since I have 1,252 business contacts and need to delete some old ones.

How and where do you have these backed up? Ex. I have VZW and an app called backup assistant which stores all contacts on Verizon's server. If i log in to VZW and go to manage contacts. Select all the ones you wish to delete and then do so. Save your changes and log out. Go back toyour phone, Open this app and hit the sync button. In minutes you will have done what you wanted to do.

Now should you not have Verizon and have them backed up to your iCloud acct. Log into iCloud and do basically the same thing to delete via WIFI on both and then log out of iCloud and they should be gone from your phone.