Please do not experiment with this stuff if you're not familiar with partitions and the way things work. You do run the risk of bricking your device permanently if you don't know what you're doing. I'll write this so that developers can start porting their ROMs to the LTE variants.
The two devices are identical except for the modem (and rild files) and the GPS initialization at bootup.
1. You'll need to rewrite the updater-script in most CWM flashable ROMs to make sure.. again, MAKE SURE that you do not flash anything else except /system /data and the boot partition. Overwriting your modem partition with a modem from the N7100 phone or the bootloader partitions will blow up your phone. You've been warned ! The partition labels and numbers are identical so you won't have to change that.
2. Make sure you bundle a kernel (boot.img) from one of I317/N7105 (depending on which device you own). Obviously we're talking about TW kernels here so for example stock JB kernels or Perseus will do just fine. Do not flash boot.img kernels from the N7100 section.
3. You'll need to add and remove a bunch of userland library files from your device. I won't attach these files here but you can grab them from any I317/N7105 ROM:
Files to ADD/REPLACE (Yes, every single one counts as they're dynamically linked). The stuff in /system/bin are started by the initramfs in the kernel so add them all in as well:
./system ./system/bin ./system/bin/qcks ./system/bin/sec-ril ./system/bin/qmuxd ./system/bin/efsks ./system/bin/diag_uart_log ./system/bin/netmgrd ./system/bin/gsiff_daemon ./system/bin/ks ./system/bin/rild ./system/bin/qmiproxy ./system/bin/secstarter ./system/etc ./system/etc/gps.conf ./system/lib ./system/lib/hw ./system/lib/hw/audio.primary.smdk4x12.so ./system/lib/hw/gps.default.so ./system/lib/hw/audio_policy.smdk4x12.so ./system/lib/libril-qc-qmi-1.so ./system/lib/libnetmgr.so ./system/lib/libaudio-ril.so ./system/lib/libloc_api_v02.so ./system/lib/libril-qcril-hook-oem.so ./system/lib/libqdp.so ./system/lib/libdsutils.so ./system/lib/libqmiservices.so ./system/lib/libqmi_client_qmux.so ./system/lib/libloc_adapter.so ./system/lib/libqmi_common_so.so ./system/lib/libqdi.so ./system/lib/libqmi.so ./system/lib/libcsd-client.so ./system/lib/libloc_eng.so ./system/lib/libqmi_encdec.so ./system/lib/libqcci_legacy.so ./system/lib/libqmi_cci.so ./system/lib/libssaudio-client.so ./system/lib/libidl.so ./system/lib/libril.so ./system/lib/libqmi_csi.so ./system/lib/libdiag.so ./system/lib/libdsi_netctrl.so ./system/lib/libgps.utils.so ./system/lib/libgps.so
4. Lastly, you'll need to change build.prop so that it loads our RILD files instead of the N7100's:
replace rild.libpath=/system/lib/libsec-ril.so with rild.libpath=/system/lib/libril-qc-qmi-1.so