Step 1: Click on Start, then on Run, and type in CMD, then hit enter.
Step 2: Now a black box will appear, type in net user and hit enter.
Step 3: Now you'll notice how all the accounts on the computer will be displayed, pick the account you want to hack.
Step 4: Now type in net user ACCOUNT NAME * and hit enter.
Step 5: It will ask you to replace the existing password, this is how we over-write it.
Step 6: Type in your new password, and hit enter, now type it again, and hit enter one last time.
Step 7: Now it should say something like command completed successfully.
Note: If the account name is two words, seperated by a space, for example Riad Sbai, then you must wrap the name with quotations. So the final like should look like net user "riad sbai" *