更换任天堂Switch Pro手柄外壳

Disassembly was fine, but reassembly was a bit trickier. Removing the front casing from the chassis as in step 8 required a bit of force, since it seemed like the two were clipped together. Putting the two together, I can't seem to find where exactly that clipping connection was. I'd ignore it and move on to the screws, but it doesn't fit flush and I'm left with this narrow gap at the top that seems to be causing trouble. Any idea where I should be looking/applying pressure?