What was the plan to bring the south back to the union?

The plan was outlined in Lincoln's Proclamation of Amnesty and Reconstruction on December 8th 1863. At least 10 % of voters that had cast ballots in the 1860 election had to take an oath of allegiance to the Union.

Also almost anybody could receive a pardon by taking this oath of allegiance.

Excluded were people that had given up positions in the federal government to serve in the confederacy, high ranking confederate military officials, and those who had mistreated black and white prisoners of war.

This answer was thoroughly processed and corrected by my mother and tediously chewed up and ruminated until it was finally approved so I'm going to hurry up and publish this before she finds something else.