Here is a good reference for re-alignment of IRS when one or both sides fail the alignment…AMM34-21-00 (710-801) Air Data inertial Reference System – Operational Test
All individual ATA chapters listed along the top – hover over numbers for drop down
Here is a good reference for re-alignment of IRS when one or both sides fail the alignment…AMM34-21-00 (710-801) Air Data inertial Reference System – Operational Test