Computer zodat to big sur

My computer is fronzen, stuck in the update. Al I have is a wi Dow, I can not even click anything, with choose startup disk, but the little update circle thing keeps turning around. Pls help!!
Did you try the usual clear PRAM ?
https://support.apple.com/en-us/HT204063
or Resetting the system management controller (SMC)
https://support.apple.com/en-us/HT201295
Computer zodat to big sur
 
 
Q