Here's a picture of one of the types I have. The circled portion is the tab. On this drawer the tab needs to be pushed upwards to release it. On the opposite side of the drawer the tab will need to be pushed downwards. It's best to deal with emptied drawers - getting them back on and aligned properly can be a bit frustrating.
2016 Tiffin Phaeton 36GH
2013 Nissan Xterra S 4WD manual transmission