1: What you need to do is go to login.live.com
go to help central (it'll be in the bottom right corner)

2: In the middle of the screen it'll say "faq": click how to add alternate email
a list on right will pop up, scroll all the way down and click get more help (in the bottom of the screen that popped up)

3: Then click get support
enter in your full name
then type in the email address u want your new password sent to
then type in the email address to the windows liveClick the image to open in full size. id that is connected to your xbl account

4: In the box under that: pick "sign in and Password"
another box will pop up under that pick: "i forgot my password"
in the big box just type: i forgot my windows live id password
in the box under that choose: first time
then type in the name of your internet service provider (i.e comcast,verizon, time warner) if you dont know your isp ,(and if u dont u then WOW), go to ipchicken.com it'll tell u your ip address and your isp.
the box under that: say NO

5: Then just type in the captcha and click sumbit
A email will be sent the email you have chosen earlier with further instructions on getting your new password. EDIT!!!: when u get the email. DONT CLICK FORGOT PASSWORD CLICK VALIDATE ID THEN U FILL OUT ANOTHER FORM AND THEY SEND YOU ANOTHER EMAIL that tells you to pick a new password and confirm. 24 hours after that they will send u a survey email asking about their customer service u can choose to ignore that if you want.

Credit to ooPRODIGYoo