What is the test for substituting a juror with an alternate juror?

Section 1089 allows for substitution of jurors with alternates, and constitutional considerations require that deliberations begin anew when a substitution is made after final submission to the jury. (People v. Collins (1976) 17 Cal.3d 687, 694.) Thus, the trial court must instruct the jury "to set aside and disregard all past deliberations and begin deliberating anew. The jury should be further advised that one of its members has been discharged and replaced with an alternate juror as provided by law; that the law grants to the People and to the defendant the right to a verdict reached only after full participation of the 12 jurors who ultimately return a verdict; that this right may only be assured if the jury begins deliberations again from the beginning; and that each remaining original juror must set aside and disregard the earlier deliberations as if they had not been had." (Ibid.)

At the time of making the substitution, the trial court instructed the jurors as follows:

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