Lowered Antenna Mod:
Inside the program folder for SH3/GWX there is a program called JSGME (JScones Generic Mod Enabler) and a folder called MODS. Inside the MODS folder you will find 'bundled' optional mods that are included with GWX.
To install the Antenna Mod, you need to unzip it to this MODS folder. Make sure the folder tree looks like this - Lowered Antenna > data > etc etc etc.
Then double click on the JSGME.exe to open the interface window. You should now see all the mods that are contained in the MODS folder on the left side of the window. To enable any mod, click on it once to highlight then click on 'enable mod'. Some mods take time to fully enable, be patient.
GWX Skin Pack:
You have 2 options here.
1) Pick and choose which skins you want and then correctly bundle them together and enable them just as above. (some knowledge of SH3 files is required)
2) Using SH3 Commander 2.7, after extracting the files they can be copied directly into SH3Cmdr's program folder. By copying & pasting the
date folder from the mod and overwriting the original in Cmdr's folder.
I would suggest that first you run at least 1 patrol before adding all the bells & whistles to make sure everything is fine & dandy.
Please make sure that you have read the readme for SH3Cmdr if you plan to use it. There be important stuff inside.
Good luck & enjoy GWX.