CodeLine® Removal Tool, part number 50303, which is available from your supplier. This can also be accomplished using a screw driver and a pair of pliers if the tool is not readily available.
Disconnect permeate piping as required at nearest convenient joint, being careful not to place undue stress on the threaded connections in the plastic permeate port.
With the removal tool the retaining ring can be lifted upward by simply rotating the tool counterclockwise after inserting it over the tab on the retaining ring (Use the smaller hole).
Hold the tool flat against the end margin and parallel to the vessel bore. It is then possible to pull the end of the retaining ring straight out. The retaining ring may snap back into the
groove if this alignment is not closely adhered to.
If the retaining ring is difficult to remove, try soaking with a release agent such as LPSTM or WD40TM, being careful to avoid any contamination of a membrane element.
Repeat above procedure for the opposite end of the vessel.