Toby:
The way a pro would do this is with something called a "toe kick saw", like this one:
'Crain 775 Toe-Kick Saw | Tools4Flooring.com'
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Or, just Google "Toe kick saw" and read all about them.
You can rent a toe kick saw from Home Depot, but if they don't have them, phone up any retail carpet or flooring store and ask to speak to the Installations Manager. Ask him who sells flooring installation supplies in your area, and whether they rent toe kick saws. Most likely, the places that sell flooring installation supplies will rent toe kick saws.
A toe kick saw will cut to a maximum depth of 3/4 inch approximately 1/8 inch away from your cabinets, so that you don't actually disturb the wood flooring the cabinets are sitting on.