As an example, I'll list my KNMM_Mk14 pack files and explain how it all works. There are seven files and one folder in the KNMM_Mk14.zip:
Unzip the pack to your KNMM folder. You should now have there the KNMM_Mk14 folder with five files inside it and two .cmd files. These command files are there to help you manage vLSO compatible stuff.
The KNMM_Mk14_Add.cmd copies files from the KNMM_Mk14 folder to their destinations as follows:
to the KNMM scenery folder
to the KNMM texture folder
From now on your KNMM scenery becomes vLSO compatible - there are three Mk14 IFLOLS at runways 01L, 19L and 28, and you can choose either of them via vLSO add-on menu (provided you are within a 6 nm range from NAS Meridian).
The KNMM_Mk14_Remove.cmd reverts i.e. removes the above mentioned files.
The key part of any of my FCLP packs are .tag files. vLSO reads a .tag file to find all the necessary info on a given FCLP site (the number of Mk14s, their locations, their glideslope settings etc.)
It should be noted that during its startup the program browses scenery folders of all active sceneries and tries to read any .tag file found there. This means that if a .tag file has the wrong format (it was created by another application, for example, or somehow corrupted) then most likely there will be errors when loading that file. My sceneries' .tag files follow this simple naming format: [ICAO]_FCLP.tag, where ICAO is the ICAO code for a given airfield. For example, KNMM_FCLP.tag for NAS Meridian, KNFJ_FCLP.tag for NOLF Choctaw, KNFE_FCLP.tag for NALF Fentress etc.
Please make sure all .tag files in all your active sceneries meet this format at least.