Here are 3 pictures of mine while it is off. The first one is from the underside of the adapter plate. Depending upon who you bought your seal from and how long it has been sitting around, you may not be able to recognize the slot in the rubber. On the bottom of the seal you should see a slot that will open as you push your finger into it. Run your finger all the way around to open it. The shaker adapter plate (not the base plate) will be slipped inside this slot all the way around. If these pics don't help, let me know and I'll see if I can take some better ones.