You access Adobe Camera Raw simply—and only—by opening a raw file in Photoshop or in Bridge.
Lightroom has its own forum, we do not deal with that cr@ppy software here. The epithet "cr@ppy software" is entirely my own subjective opinion of that application.
The Adobe Camera Raw plug-in can be hosted either by Photoshop or by Bridge,
It is foolish to run Photoshop and not use Bridge. Bridge is nothing more than Photoshop's file browser.
You do not "switch to" Bridge. You are being silly in your untenable stand.
Unlike Lightroom, Bridge does not hide or move your images in "Libraries". It shows them to you wherever the heck you put them or feel like putting them.