Removing the Toolhead Circuit Board
Step 1: Remove the Toolhead Housing
Please refer to the wiki page Replacing the Toolhead Housing to remove the toolhead housing. https://wiki.bambulab.com/en/p2s/maintenance/replace-toolhead-housing

Step 2: Remove the TH Board
Open the connectors of the TH board FPC cable and the extrusion motor cable, then disconnect the cables.
Remove the foam and tape from the TH board one by one, then disconnect the hot-end heating assembly, hot-end cooling fan, and eddy-current coil. When disconnecting the hot-end fan and eddy-current coil cables, pull them perpendicular to the connector. Do not apply force or shake them left or right to avoid damaging them.
Use an H1.5 Allen key to remove the four screws (BT2x5), unlock the TH plate, pull out the tool head cable, and then remove the TH plate.
Step 3: Remove the extruder Interface Board and TH Board FPC Cable
Open the cover of the Hall switch board assembly connector and disconnect the Hall switch board cable.
Note: Some machines have black glue applied to the connector. Use tweezers to remove it and then open the connector. No additional glue is required when reconnecting.
Use an H1.5 Allen key to remove the two screws (BT2x5) securing the extrusion interface board, then remove the extrusion interface board.
Open the connector tab on the back of the extrusion interface board and remove the TH Board FPC Cable.