Q: how to unlock iphone without a computer?

You will need a computer to restore the phone if you forgot the passcode or the phone is disabled

If you mean unlocking your carrier, I may be wrong but I think it's illegal. They might have gotten rid of the law but last time I checked it was.

If you mean unlocking your passcode, you might be able to do it with iCloud's Find My iPhone, again I may be wrong, otherwise you will have to restore it.

No matter what kind of unlocking you mean you cannot do it without a computer.

Carrier unlock can only be done by the carrier it is locked to.

If the screen is locked you also need a computer: http://support.apple.com/kb/HT1212

As mentioned by others you need a computer. You could perhaps use a friends or try going into an Apple Store or an Apple Reseller and they should be able to help.

This article also may help although it is a little out of date:

https://www.netchimp.co.uk/webdesign/iphone-ipad-ipod-touch-tips/unlock-ios-8-ip hone-forgot-passcode/

I Have the same situation only aim on an IPhone 6.! I'm using my husbands phone to communicate but I need to unlock mine

See above. Same answer.