step 2: make 52 bars of right expansion.
go to style/settings/time axis and set the expansion to 52 as in the picture:
one can select more but the seasonal projection will stop after one season of time. selecting less will hide part of the projection but why? the magnification controls on the thinkorswim charts are superb. furthermore, you can select keep time zoom as i have in this dialogue, which will retain the zoom when you switch equities.