Brother GTX-4 Instruction Manual page 271

(4) Pinch the latch at the front end of ink pouch, and draw out the white ink pouch from the cartridge.
<TIPS>

Remove the accumulated ink at the tip of the cartridge with a waste cloth (non-fuzzy cloth).
Cartridge's tip end
(5) Put the capping pouch in the cartridge.
Push the tip end of capping pouch into the cartridge until it clicks into place.
Straighten the capping pouch in such a manner that it will be aligned with the gutter of lid of cartridge, and mount in position by
pulling it with your hand.
<NOTE>

If the edge of the ink pouch is bent or undulating significantly, make it straight with your hand.
Capping pouch
(6) Put the capping pouch in its correct position.
<CAUTION>

Avoid touching the portion (a) of cartridge. Otherwise, you may cut your hand.
(7) Close the lid, and put the capping cartridge in position inside the printer.
(8) Repeat the same process to replace the other white ink cartridge with the capping pouch.
White ink pouch
Cartridge
(a)
Align lines with
each other
271
Cartridge
Latch
Place the pouch in straigh alignment with the cartridge
Troubleshooting
X0119
Stretch
X0049
X0041