In pic 3 there appears to be a hex nut behind the faceplate. I would hold it with a wrench and try to remove the faceplate with a strap wrench.
There appears to be a small pin (spindle lock) just above the hex nut. Try to push it in and rotate the spindle and see if it engages. If so you won't need a wrench for the hex nut.
They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety. Benjamin Franklin