You can also use the film leader from another canister, as shown in this video. The steps are as follows:

1. Wet the emulsion side of the film leader to make it sticky (saliva or water will do the trick)
2. Inserting the wet leader in the fully wound canister
3. Turn the wound canister reel clockwise a few times
4. Pull the wet leader out in a quick swift motion

If it doesn't work on the first time, don't hesitate to repeat all of the steps above.

You can also use the film leader from another canister, as shown in this video. The steps are as follows:

1. Wet the emulsion side of the film leader to make it sticky (saliva or water will do the trick)
2. Insert the wet leader in the fully wound canister
3. Turn the wound canister reel clockwise a few times
4. Pull the wet leader out in a quick swift motion

If it doesn't work on the first time, don't hesitate to repeat all of the steps above.