Looking for advice:

I have a heavily planted 75 gallon aquarium with about a 1.5 to 2 inch layer
of Flourite on the bottom of it. On top of the Flourite is an inch to 1.5
inches of sand. I have had it this way for about a year now. The sand is a
real pain to keep clean without disturbing it too much. What I want to do
is somehow remove it and replace it with about 1.5 inches of pebble gravel.
In this way I will better be able to clean it without having a big
disturbance inside the aquarium. Does anyone have any ideas how I can
remove this sand without disturbing the waters too much and then replacing
it with the pebble gravel. Your advice is appreciated.

Dan