Hi dude I'm just on my way out to work but ill get you dimensions later, sure its roughly 6'' mounting depth from outer face to the inside of the base. Can't remember the volume though,about 0.65cft iirc.
It hasn't got any fixings on it,pretty sure its that tight in there that it wouldn't move about lol. As far as the stock removal that's pretty easy,remove the panel on the drivers side, remove the front fascia which leaves you with a metal plate,undo the bolts and ta daaa lol
Hth for now dude