Can I watch the changing of the guard from an elevated position?

I have a Nikon D5100 and I would love to film a miniaturized "Changing of the Guard" at Buckingham Palace. Is there any pllace I could shoot from?

Across the street?

I was there a few months ago. My recollection is that there really isn't anywhere you can access that gives you any significant elevation. The only tall building in the area is Buckingham Palace, and specifically a portion that you can't access from the public tour.

So my response has to be 'No'.

Short answer is no.

There isn't anywhere convenient in the immediate area to record from, and you will probably have to work from a Cherry Picker. The area directly outside of Buckingham Palace is administrated by the Royal Parks, and you will need to liase with them and the Metropolitan Police to acquire the necessary filming permits.

Since you sound like you are just an amateur, and do not have a Hollywood sized budget, I'd imagine you probably won't want to go to those lengths.