Here are instructions, along with some pictures for making rose petal preserves : )
This recipe is thicker than your typical rose petal jam.

Rose Petal Preserves

Ingredients:
4 oz Rosa Damascena Petals (about 8 cups loosely packed petals) 
1/2 Cup Freshly Squeezed Lemon Juice (about 2 medium lemons) 
1 1/2 Cups Cold Water 
2 Cups Sugar 
1 Packet Powdered Fruit pectin

Gather only the petals from the roses. Rinse petals well with cold water in a strainer or colander. Place in a large shallow saucepan.

Drain well.

Add to the petals lemon juice, water and sugar. Mixture should be more shallow than deep.

Stir over heat while slowly bringing to a boil to dissolve the sugar. Once sugar is dissolved bring to boil, reduce heat and simmer gently, covered for 30 minutes.

Blend the fruit pectin with some of the liquid from the pan, add this mixture back into the pan and stir without boiling until fully dissolved.

Bring back to boiling, reduce heat, simmer gently for a minute or so.

Pour into hot, sterilized canning jars, invert to seal. Store in a cool, dark place.