1) Extract the GMC.zip file into an empty directory.
Content:
OTA.asc Operational Transconductance amplifier (symbol)
OA.asc: Operational Amplifier (symbol)
filters.lib: Library file including the subcircuits implementing the OTA and OA
test_OTA: Test-Bench to simulate the OTA
test_OP: Test-Bench to simulate the OA

OTA e OP are ideal blocks with the following parameters:
OTA: Gm, max-input voltage (vim) max-output voltage (vom), dominant pole (fp) dominant zero (fz)
OA: DC gain (Ao), gain-bandwidth product (pgb) max_output voltage (Vmax)
Maximum voltages are symmetrical (-Vmax, +Vmax etc)

2) Extract the pack_LTspice_2.zip into the same directory as above:

Content: 
filters.lib  Updated filters.lib version, to replace previous one
ck_2ph.asy   two non-overlapping phase clock generator (symbol)
sW_ideal.asy Ideal switch: closed for control signal > 0.5, open otherwise (symbol)
sw_ideal.asc Schematic of sW_ideal.asc