Brother GTX pro Instruction Manual page 170

(2) Open the cartridge's lid.
<IMPORTANT>

When opening the lid, be sure not to touch the portion (a). Otherwise, it could be damaged.

Place the entire cartridge on a flat surface, push the latches on the bottom surface of the cartridge downward and open the lid.
Cartridge
(a)
(3) Pinch the latch at the front end of ink pouch, and draw out the depleted ink pouch from the cartridge.
<CAUTION>

Remove the accumulated ink at the tip of the cartridge with a waste cloth (non-fuzzy cloth). Clean the printer on a regular
basis.
Cartridge's tip end
(4) Unpack a new ink pouch from its shipping carton.
For the white ink pouch, shake it 100 times each in the side to side direction with its obverse side and reverse side facing upward
separately, as shown below.
<NOTE>

Shake the pouch under the condition it remains contained in the inner box.
Precautions to keep good printing quality/use printer over the long term
Lid
Ink pouch
White ink pouch
170
Latch
Cartridge
Latch
Lid
X0042
X0119
X0048