about 1/2-cup to 1 cup of sugar. while that may sound like a lot its not, as it will all cook down, and the sugar will make it jell in this recipe.
cook the mixture at a medium-high heat. you want a low boil that will not boil over (your pan should be big enough so that it has high sides and room). watch it. cook it stirring occasionally, for about 40-45 minutes total. check it and stir it every 10 minutes. what you want is for it to all fall apart, and the fruit to mostly disintegrate. what looked like a lot of fruit will become a much smaller amount 