You can easily move pages to change their order in Publisher with a few clicks of your mouse.
Right-click to move a page
On the page sorter, right-click the page number that you want to move, and then click Move Page on the shortcut menu.
In the Move Page dialog box, select the options that you want, and then click OK.
Click and drag to move page
You can also move a page by clicking the page on the page sorter and dragging it to a new location on the page sorter.
If you are in two-page spread view, you should move both pages of a two-page spread at the same time in order to avoid splitting up any two-page spreads.