How to take the password of my iPhone?

I have an iPhone 4s and I just changed the password on my phone. I guess I wasn't paying attention when i changed it and i have no idea what it is. My iPhone is backed up to my computer and I tried to restore my phone to the lastest backup but it says there isn't enough free space available on my phone. Is there any way I can take the password off my phone from my computer?

You shouldn't need anymore free space to do a back up. Are you sure that's the back up from your phone and not someone else's?