It's hard... requires cross compiling and linux kernel development setup and knowledge, with mkezx toolchain i guess.
(It's a patch against the kernel driver, so you need to rebuild the kernel after patching...)
I'd like if there was any tutorial,
afaik, there is the motorola .doc in the kernel sources, but it's quite useless

. And also, the kernel released by moto is
afaik not functionnal, if you compile it without changing some bits....
I never been able to build anything for my A910, at least, but is it better on A1200??.