How to get rid of somebody elses info in my used iphone?

I purchased a used iphone and when trying to download my apps etc, its asking me for a password to the old dudes account! How do I get rid of this and get my own info in there?

Go to settings, general go down all the way to the bottom and hit reset

You will need to do a master reset, on an iPhone, you would go to Settings>General>Reset>Erase all content and setting.
on an android 4.2.1 you go to Settings>Backup and reset>Factory data reset.

other than that, I'm lost.
hope this helps,
if it doesn't, you should tell people what kind of phone you have

Go to settings and if there's a place called privacy go to. All phones have it, you just have to find it
In there you will find something get that says "factory data reset* if you do that all the information should be gone.

  • Which is more accurate regarding the details of an iphone, iphoneimei.info or imei.info? When I look up the IMEI of my broken iphone 5s on iphoneimei.info it says it's 16gb and when I look it up on imei.info it says it's 32gb… Which site is more accurate? The iphone is stuck in recovery mode and will not power on unless connected and it won't tell me the storage capacity in itunes.
  • What happens if you put someone elses apple ID into your iPhone? If I put a friends apple ID into my phone will I receive their imessages? Will they receive my messages? Can I still text all my friends with iPhones through SMS from my actual cellphone number?
  • Is anyone elses Iphone 5 random with battery usage? About a week ago. I had accumulated 8 hrs and 20 minutes usage and 3 days 5 hrs stand by time before it was about to die. Today I have almost 6 hrs and 3 days stand by and the battery is at 10%, It seems like the battery usage is really random. One day I have an extra 2 hours talk time the next day my phone dies alot quicker. Could this be from not exiting out apps when i'm not using them or is the Iphone 5 just weird like that?
  • Is anyone elses iphone 4s going slow? After ios7 update everything seems a little slower on my iphone 4s. I don't have much on it either to be honest.