When they're as ripe as you want them (not too soft, as they cook in the water bath & soften more) drop them in boiling water ( a few at a time) for a minute or so & them put them in ice water - the skin will come right off. Then you score around the peach with a knife - right to the pit. Grab with both hands & twist & it should come apart in half where you can cut out the pit. I then drop the 1/2s in cold water with lemon juice to prevent browning. I have never heard of not using a sugar syrup - maybe you can substitute Splenda?
Go for it & good luck!