Usually with the Samsung Galaxy Tab, Galaxy Tab 10.1, Galaxy Tab 10.1 2 you just have to get a pry tool and go around the plastic edges to pop off the case. The Galaxy tab 10.1 2 doesn't have any external screws so I dont think the Tab 2 will either. But to check for screws look for little plastic circles on the bottom or around the case, if you see some then there will be screws under them.
Just go around the edges with a thin tool and pop off the case, should be all you need to do. You can be rough with it(not too much), you wont break it unless you really flex it.
If you wanna post some photos of the edges and where the glass meets the plastic I could tell you for sure.