How to figure out the password to my iPhone?

I have an iPhone that I recently found after having lost it for about a year, but now my password is unknown to me. If you happen to know a way to figure out the password, please answer as soon as possible.

Also, the phone keeps having the emergency call option pop up, plus it won't let me enter in the passwords that I'm guessing. It says "iPhone is disabled- connect to iTunes." Help!

Added (1). Some more details, just in case-

8 gigabytes
Designed by Apple in California/ assembled in China

Added (2). I was thinking about hacking into it, but I don't know how to… Any ideas are appreciated.

It wouldn't be a password if you could easily just figure it out.

Plug the device into the computer you first synced it on, and it should be unlocked,
of that doesn't work try this

tern the phone off
hold the home button and plug into iTunes.
this will enter into recovery mode, from there itunes will ask you if you want to restore and update the device.click yes. Then it will start downloading the software and restoring it.
NOTE. THIS WILL LOOSE All PREVIEWS DATA. It will be like when you first got the phone.