Your brief post raises a great number of issues. As you know, I view human emotion as the confluence of three quite different streams---hardware (brain and body stuff), firmware (the innate programs that remap the face into patterned displays for each of nine affects), and software (the way we've been raised in a family, a neighborhood, an era.) By introducing this language, I've unintentionally perpetrated confusion about the difference between affect and script. After infancy, when the child has little ability to correlate experience in order to alter action, all affective display involves learning and thus must be described as a script. Scripts, says Tomkins, are rules for the management of affects within scenes, and it is through these scripts that we live our lives.
You ask how we as therapists "rewrite a script" for another person. Tomkins, who entered college thinking he would become a playwright (who would therefore create scripts to be read by others), used the language of this first love when he developed the concepts of affect and script theory. Yet the scripts that each of us reads in order to become the actors of our own lives are not material written for us by others but the result of unconscious action as the mind assembles scenes containing affective experience into clusters that may be managed by rules. It is not possible for us to rewrite anybody's script, even though our operation as therapists allows people to rewrite their own!
Let's then take the matter of a patient with bipolar affective illness, someone whose affective experience has been rendered non-ordinary by some glitch in the circuitry for the affect interest-excitement (inappropriately intense in the manic phase, inappropriately sparse in the depressive phase). I'm sure you remember my image of the affect system as a bank of nine spotlights, each of a different color, each turned on and off by different triggers, each motivating us to act on that trigger in a completely different way. Bipolar illness messes up one of the spotlights in such a way that the individual is constrained to develop life scripts that take for granted the type of affective reaction that person was forced to live with. If by introducing Lithium salts or anticonvulsants we allow the bank of spotlights to operate more normally, then the individual will become able to understand life quite differently. I had the opportunity to work with a number of such patients in the late 60s when we began to use Lithium, and marveled at the fact that for the first two years after starting Lithium, these people were able to learn a tremendous amount about their emotions, learn how to identify them, when to expect them, how to identify them in others. Often I felt that I was a more or less passive guide useful to them for explanation of the new phenomena they were now able to observe. The scripts they developed (I didn't know Tomkins's language back then) were made possible by the pharmacologic release from the old pattern of affective experience. As happens so often in psychotherapy, we don't teach or write scripts as much as help people understand their experiences in ways that assist them to build their own scripts. To the best of my knowledge, no one has had much success in assisting new script formation in Bipolar patients who are not taking medication, simply because the large part of their affective experience is governed by the glitch that discolors interest-excitement.
Sexual trauma? Relational difficulties? Work instability? All these may be addressed best when the affect glitch is controlled as best as possible (I don't think any current medication provides full normalization) and probably not usefully when the patient isn't taking medication. I view the recently medicated Bipolar patient as one of the luckiest people alive; able to learn for the first time in areas previously invisible and illogical. Therapy, as you hint, is long hard work when you start with someone who is newly come to the land of affective stability. But at least it is possible. Whatever you do to teach about the normal triggers for affect, indeed, whatever you can teach patients about the nature of their affect system, will allow growth and redevelopment previously impossible. Then you will have assisted an individual to write new scripts for a new life. Not a bad result.