That is the big question that concerns many but this might help:
The process with impressions must be automatic so that you no longer have to deal with it at ctb
Because the easiest way to overcome SI is when you act impulsively when you are angry.
If you sit quietly and think about life that you lose with the ctb, think about your family and friends, then the SI gets bigger and bigger.
But if you think about everything bad that got you there, about the people who caused you pain, then you can build up anger.
Anger at this life that you finally want to end.
The more bad things you imagine, the more anger you can build up if you just want to be gone and call up the automated process. Including deduction.