SoftBank 304HW User Manual page 122

120
Changing PIN
Change PIN. PIN can be changed when PIN verification is enabled.
In Menu List, "Mobile Network Setting" "PIN Management"
➜
Set "PIN verification" to "Modify" Set required items "Apply"
➜ ➜
PIN is modified.
・ For setting values for PIN, see "WEB UI Settings (Setting Range/Default Value)."