hi tsunami,
nice to see you here on BBMD and read your post........
hm... let me see what we can do
but first some questions.
1.) is this for a spearhead or a breakthrough-server?
i really dont know very much this released demos, but i guess... it was for spearhead
2.) i see there 3 moddifications....
- snow falling down
- a banner with "happy 2010" over the bridge
- some kind of lightdots on the balustrade
is that right?
3.) this mod is running on a private server... means..... moddification runs on your local-mashine well?
4.) then you put this mod. script and all the other stuff - f.E. textures, shaders, other files - in a valid pk3 in right folder-stucture?
give the pk3 a name like "zzz_my_modd.pk3".... for example, restart the server?
anyway i am not sure about the fact, that a demo accept modded files.... but you wrote something about a weapon-mod. if this work, it might be possible.
one more question. weapon-mod means, that you dissable the "granatwerfer" on both sides too?
btw....... moddifications like yours are not really "noobs job"..... you are a little genius ... i guess 
lol ... nice idea to let it snow in malta. in reality i guess, the people from malta didnt see snow for the last 1000 years.
p.s.: my english is also not the best one...... 