Hi there, the menu has absolute position so to move that down I’d suggest changing the value for top inside the css for the menu container.

#menu-container-border {
top: 36px;
}

To change the height of the logo container try the following

#logo-container {
height:200px !important;
}

To center the menu I would advise changing the margin on the left of the menu container css. Change the 25px to another figure or % value.

#mainmenu ul.menu {
display: inline-block;
margin: 0 0 0 25px;
position: relative;
}