Answer by
LeheckaG (1826)
"Best-way" is installing builders'-support-jacks,
and (one-section at a time):
excavating exterior,
re-builing basement-wall,
and back-filling.
More commonly:
exterior is excavated,
anchor-plates are set on both-sides of basement-wall,
and anchor-plates are gradually screwed together pulling basement-wall back into place.
Your "Poor-drainage" problem needs to be fixed;
freezing/wet-soil usually bows basement-walls.