Hey thanks a lot for the detailed instructions! Not many people would bother helping, I really appreciate it!

You can do it manually but you need a program called crowbar it should be the 2nd link on google. If it's not look for a steam page. Once you have downloaded it go to your steam folder then the steamapps folder, workshop, content, 2177760, 3486799658 there should be a .vpk file in the folder. Open the .vpk file with crowbar. In crowbar open the models folder and then the weapons folder. there should be a lot of files select the ones that start with vr_smg and drag them onto you desktop or whatever. for the textures do the same thing but instead of the models folder go to the materials folder then in the materials folder the models folder and then the weapons folder. drag the vr_smg folder onto your desktop. And that should be it. If you're having any problems let me know and I'll try to help you.

This is most excellent, thank you. Is there a chance you could upload individual guns for individual replacement? For instance I only need the MP5. Is there a way I can do it manually perhaps? I don't know much modding.

neither would be the gluon gun, but atleast both options wouldn't look out of place compared to the other weapons.

replacing the gravity gun with the tau cannon doesn't really make much sense but it might be kinda cool anyway

very neat.