A couple of tips:

- You DO need a technician's razor with a flat! I’ve tried multiple plastic tools and even a knife - I couldn’t detach the screen. Partially, because the gap is so narrow. It’s very easy with a flat blade!

- (DO IT AT YOUR OWN RISK) I didn’t have an iOpener so I put my watch in a ziplock, put it in a cup, poured hot water (~100C) and left it for ~3 minutes. It was very easy to detach the screen with the technician's razor with a flat, and it simply popped out! my screen is still working and there no cracks :)

Amazing guide! I was able to replace my ionic’s battery and it’s working again, thanks!

The symptoms my ionic had: the watch worked only when it was plugged into the charging cable. As soon as I remove the charging cable it shut down. Ionic did show that it’s charging when it was connected to the charger but it failed to charge even after I left it charging for more then a day. I tried soft/hard factory resets, replacing charger, replacing battery and nothing helped. So I decide to buy a battery and replace it myself and it finally resurrected my watch :)

Because fitibit didn’t have the battery available, I ordered HSABAT IONIC 500mah from ali. I’ll try to leave a comment after I use it for some time. At least my ionic is holding a charge right now :)