Just right click in the channel view, then select Add Modes/Remove Modes, then select the mode you'd like to add/remove!

Menu Channel {
  .Add Modes
  ..ANSI Block:/mode $chan +c
  ...CTCP Block:/mode $chan +C
  ....Flood Protect:/mode $chan +f
  .....G Rating:/mode $chan +G
  ......Invite-Only:/mode $chan +i
  .......No Knock:/mode $chan +K
  ........Key:/mode $chan +k $?="Channel Key"
  .........Limit Redirect:/mode $chan +L $?="Redirect Location"
  ..........Channel Limit:/mode $chan +l $?="User Limit"
  ...........Registered Nick To Talk:/mode $chan +M
  ............Voice To Talk:/mode $chan +m
  .............Disable Nick Change:/mode $chan +N
  ..............Private Channel:/mode $chan +p
  ...............Channel Peace (No Kicks):/mode $chan +Q
  ................Registered Nick Required For Join:/mode $chan +R
  .................Secret Channel:/mode $chan +s
  ..................No Channel Notices:/mode $chan +T
  ...................Strip Formatting:/mode $chan +U
  ....................Block Invites:/mode $chan +V
}
Menu Channel {
  .Remove Modes
  ..ANSI Block:/mode $chan -c
  ...CTCP Block:/mode $chan -C
  ....Flood Protect:/mode $chan -f
  .....G Rating:/mode $chan -G
  ......Invite-Only:/mode $chan -i
  .......No Knock:/mode $chan -K
  ........Key:/mode $chan -k
  .........Limit Redirect:/mode $chan -L
  ..........Channel Limit:/mode $chan -l
  ...........Registered Nick To Talk:/mode $chan -M
  ............Voice To Talk:/mode $chan -m
  .............Disable Nick Change:/mode $chan -N
  ..............Private Channel:/mode $chan -p
  ...............Channel Peace (No Kicks):/mode $chan -Q
  ................Registered Nick Required For Join:/mode $chan -R
  .................Secret Channel:/mode $chan -s
  ..................No Channel Notices:/mode $chan -T
  ...................Strip Formatting:/mode $chan -U
  ....................Block Invites:/mode $chan -V
}