The thing with the black handle is a "multi-tool wrench" with a 10mm socket attachment attached to it.
Insert and 10mm wrench on the bolt head. Use your 10mm socket tool to turn the nut.
When re-attaching, you may want to have flip the nut/bolt direction to whatever direction is easiest for you. Personally, I keep the nut at the bottom.
I have also come across a few newer Celica models which have switched from the bolt/nut attachments to a bolt/plastic-retainer. If this is the case for your setup, only a 10mm socket is needed.