How do I degloss my shiny bike? I have a Tomasso Sterrata.

I love the bike, but I don't love the paint job.

I think I would like the paint job more if it weren't so glossy. (This year's model has a matte finish of course, but I have last year's model.) 

What can I do to give it a more matte finish without covering up the existing color and decals?
If you really want to paint it, you can try to wetsand it to remove the clear coat, and then refinish it with some matt finish clear coat. This is a risky move if you're not experienced with painting cars or stuff. You can ruin your bike real quick.

The safe method, and easiest one, would be to wrap the bike with some matt/satin finish clear vinyl (here is an example). It is often used on cars by people with the same issue as yours, and would perfectly do the trick on your bike. Plus you can remove it whenever you want, and it will protect your frame. It's a win-win.