# see available connections
nmcli d wifi

# disconnect from the access point you are currently connected to
# replace <current AP> with the AP you are currently connected to
nmcli c down <current AP> # see previous command output

# connect to new AP
# replace <AP name> with name of AP you want to connect to
# replace <password> with the password of the AP
nmcli d wifi c <AP name> password <password>

# hope this helped you :)