The Grinch Kernel 19.3.8 & OpenCV

Summary:
Need to run both SPI & OpenCV in Jetson TK1. First, I successfully installed The Grinch Kernel with SPI support, as instructed:
http://neurorobotictech.com/Community/Blog/tabid/184/ID/12/Using-the-Jetson-TK1-SPI–Part-2-Configuring-the-kernel-for-SPI.aspx

OpenCV was missing after the installation. Tried to install optimized OpenCV4Tegra as instructed in http://elinux.org/Jetson/Installing_OpenCV and got the error:
dpkg: error processing archive libopencv4tegra_2.4.10.1_armhf.deb (–install):
cannot access archive: No such file or directory
Errors were encountered while processing:
libopencv4tegra_2.4.10.1_armhf.deb

Then updated the Jetson with sudo apt-get update, now the Jetson is in infinite login loop.

Question:
How should I install OpenCV? Please note that OpenCV efficiency is quite critical for my high speed camera application.

Thank you