Anything can be resized up to a certian extent, but yours will probably cost a lot more then usual due to the fact they have to work every joint to resize it evenly. It might not be worth it after you get an estimate for the cost.
The problem is that they might not be able to remove just the right number of "flowers" to size it to the correct size...it''s not an easy job for sure, and some jewelers might even tell you no, so just be aware.
Hi,
by the looks of the band I don''t see a problem of sizing it down. you need to bring it to a good jeweler to see how many sections he would need to take off without ruing the design. There is one jeweler in my the building that does great work with platinum his name is William. If you are in the area I would introduce you to him and you can consult with him prior to the job. He does a lot of my work and you can trust him to do the great job.
Good luck