How can I remove a blank homescreen page once I've moved all the apps off it I've consolidated my 5 'pages' of apps into 3 pages.

Now I have two blank pages that have no icons in them.
These are the pages that are represented by the small squares on the home page screen that take you to these various pages that have colletions of app icons.

Having moved apps/icon to other pages, the last two pages are now blank.  How can I actually remove them?

This is a Samsung Galaxy s5 running Android 4.4
Go in your home sreen, push the settings button for 1-2 seconds or try to zoom, and then all your pages will appear, now you will be able to delete the pages you don't need anymore by clicking on delete or maybe there is a button in the top right corner.

Hope it will help.