I need white frame around the screen instead of black

In my understanding the black margins around the screen are mistake.

I currently use programmable Metawatch with white area around the screen and white strap.

Is it possible to order the customized Bangle js 2 that is totally white ? :-)

If not then is it possible to disassemble it and somehow replace that black film with white one ?

If not that is it possible to order it part by part and somehow assemble totally white device ?

The black coating is directly on the glass and between glass and the digitiser. Those are glued together by optically clear resin, probably UV cured. It is possible to separate them with a nylon string used as a kind of string saw. The digitiser however is extremely sensitive to any damage. You would need to get some of that resin to get it back together.
It is probably easier and a lot less risky if you get someone to cut you a white vinyl sticker to put on the glass with a vinyl plotter and maybe try to paint the case white. Take caution to not get the button stuck with paint.

Thank you very much for information
Seems like painting is the most viable solution.
Then what is that "glass" and which paint will stay firm on it ? :-)

The glass seems to be actual glass. I think the best way for good and smooth surface would be the vinyl sticker on the glass and spraypaint for the rest. If you do not have access to a plotter, some scissors, a sharp blade and steady fingers should work as well.

I my understanding the glass is not flat - what will happen to vinyl sticker at the rounded edges ?

I would think it to be flexible enough. At least when applied with a bit of temperature it should wrap fine. I have applied hydrogel screen protectors that way which worked fine. You will have to try that, worst case it does not stick well and you are back to trying paint or something.

I think it's going to be super tricky to try and change it yourself as has already been mentioned, so vinyl/paint is probably the best bet.

However you can buy replacement screens from us for not that much money: https://shop.espruino.com/banglejs2-lcd

So you're welcome to buy one and see what you can do. If you break it (which is quite likely!) then it's not like you've lost that much.

If you could sell naked parts separately like battery, mainboard, screen, touchscreen - without glass then people would be able to insert it into their own custom cases, attach to their own glass, etc.

We sell the button and screen separately, but I'm afraid there's just not enough demand for me to stock everything separately. Plus the screen assembly (LCD+TS+glass) comes in one piece, so it wouldn't help you with this anyway I'm afraid