My husband is a jeweller and even I cant trade up my diamond without it being so not worth it.
First of all you will need a report preferably from GIA or else your specs are just your word. Any other lab report is also dubious in how accurate they measure the specs.
Although your diamonds are fl, not many people want to pay for a feature that is not visible with the naked eye. The size of your diamonds are not in scarce supply or high demand (it needs to be over 1.5 c.) and there are many on the market, so you will not get a high wholesale price.
I would either keep them for one day, as side diamonds to a centre stone, or sell them on consignment in a store where the seller will keep a %. You could try a trade up with the seller who would still enjoy the extra business.
Good luck and let us know what you do.