I just fixed this same issue. I bought a repaired unit ($200) on Ebay with a core charge ($75) and took it to a shop to be properly replaced. Sorry I cant help with the procedure but its been around 3-4 days since the repair and I have yet to get the dreaded ABS/ brake light combo yet 🤞The repair should only cost you $200-300 labor for a shop to properly replace the ABS unit and give you back the core.