A simple correction on a wordpress plugin

I have a wordpress plugin that was developed by a Freelancer member. The plugin is working well but I need some simple fast changes on the interface and backend, about 2/3 hours of work. Please apply only if you can do the work immediately. This is what I need: Frontend: - center the field password; - change the filter image with a blur PNG; - double the sizes of the two rows "Don't have your key? - Contact us" - accept in input only 6 chars and make the check after the 6th char; - give an error message "Invalid key" if the PIN is wrong. Backend: - PIN is not generated manually but is inserted by the administrator; - PIN is 6 chars numbers, letters and case sensitive; - when we save the PIN usage, save also the user IP address; - in the Settings add a field for the URL to address the button "contact us" of the homepage.