I'm having this exact same problem. I have a full glass shelf without those buttons to remove it. Salsa spilled on the shelf and the liquid got between the glass and plastic. I have to clean it but I'm unable to get it out to do so. Calling customer service didn't help one bit. This fridge is only one month old.
Check out this page from the User Manual. It may help.
Removing it is totally different from installing it. This post is totally irrelevent. The point is there are no buttons to push, just tabs that don't budge no matter how hard you push them. Bad design.
Something spilled in our fridge and some of the liquid got under the glass shelf that is above the produce drawers. We have tried several times in vain to lift the glass to clean under it, but haven't been able to. Any help would be appreciated. RF28R7351SG/AA