Installing Digium's HPEC on freepbx distro

Hello I am running into bad echo problems that OSLEC does not succeed in eliminating. more on that at Distorted echo inside the network on FXO channels

i purchased a Digium VPM100M card which is not being automatically detected as i thought should be the case. and i purchased Digium’s HPEC which should be installed following these instructions>>>

problem is that the instructions refer to the dahdi-linux-complete source package which does not seem to be in the freepbx distro (

anyone more comfortable with the freepbx distro to guide me through installation?
Thank you