Error in first message. Should have read
"is there a way I can paste my admin password in the dialogue box when changing password. I have to do this manually and it does NOT recognize the password?
Why do you suspect your neighbour has access to your WiFi?
Which password are you changing the admin one or wireless?
I have merged your previous posts as they all seem to be related to what you perceive to be happing and it may give an insight to those that are trying to help.
If the "hacker" has both you will need to change both. If the hacker only has one you need to change that one. If you don't know which if any the hacker has you should change both.
Beaware that any wireless devices of yours will be disconnected until you enter the new wireless password to allow them to connect.