This Articale discrable : How to Remove Icloud & Uefi password ( IMac / MACBOOK ) .
1. Make a Backup BIOS With Your Tool Programmer.
2. Open BIOS With HXD and Remove Password.
3. Rewrith your Edited Bios And Work is Done.
Need a skill of a Qualify Technician at The Level of Repair ( Reading/Writing Eeprom , Desoldering And Soldering ON SMD Circuit ) .