ThinkPad W540/W541 can't disable Nvidia K2100M use acpi_call

My laptop is ThinkPad W541,it have two graphics card -- intel graphics card and nvidia graphics card(Quadro K2100M), you can't disable anyone of them in BIOS.:(
My FreeBSD version is 11.1, I want disable nvidia graphics card like use bbswitch in Linux,so i found acpi_call package in freebsd11.1 and and and, all of theme don't work for me, so any idea?:(
This is my first thread and my english is so poor.;)
however, thinks for your time to read.:)