Make some small jQuery/CSS changes to a website -- 2

I am developing a new website at [login to view URL], and I want a couple of small jQuery & CSS changes making, as described: 1. When the user hovers on the grey square and the navigation appears, I want the navigation to stay fixed when the cursor moves ABOVE the div. Currently it retracts to the smaller box. 2a. When the user hovers on the grey square and the navigation fully appears, I want the logo to change to the following image ([login to view URL]). This should be done with jQuery fadeOut and fadeIn, and only when the navigation has appeared 100%. The navigation also appears when the user scrolls down the page, so the logo change should happen in this instance also. 2b. When the cursor moves off the navigation and the grey square re-appears, I want the logo to change back to the original ([login to view URL]). This should again be done with jQuery fadeOut and fadeIn, and start straight away. I have attached example screenshots for reference. We can also let you know the relevant JS file where the changes can be made. Wordpress logins and FTP details will be provided to the chosen freelancer. This should be a relatively simple and quick job for the correctly skilled person.