What was found
(AIRCRAFT NOT GROUNDED) DIRTY SOCK SMELL OCCURS ON APPROACH INTO SBN / PERFORMED PHASE 3 TASK CARD W.O. 21-000-003 NO ODOR DETECTED, THIS CLEARS MEL 21-52-01E MDDR #221523 M PROCEDURE REVERSED PLACARDS REMOVED. REMOVED APU IAW AMM 49-11-11-000-004-A. INSTALLED APU IAW AMM 49-11-11-400-004-A , COMPLETED STEPS A - E FROM AMM , OPS TEST STILL REQUIRED. STEPS F-N NEEDS TO BE COMPLETE IT FROM AMM 49-11-11-400-004-A. FOR OPS TEST OF APU INSTALLATION. COMPLETED STEPS 4.A.F THROUGH N IAW AMM 49-11-11-400-004A. OPS CHECK GOOD. NO LEAKS DETECTED AT THIS TIME.