Add custom player models to DarkRP?

I have been trying to add models for the past 3-4 hours, no luck.
I am trying to add police models, and I’ve tried two things and I’ve double checked each time.

The models came as an addon, so I took out all of the files and placed them in the servers folders. The players show as errors.
After that, I tried putting the original addon into the addons folder - no luck either. Errors showed in place of the model.

I would really like to get this show on the road, but I’m not sure what’s wrong.
Any ideas?

Edit: Also - I’m looking for someone who is good with uploading/configuring fastdl to be a mod.(even though our server automatically sets up fastdl for everything)

possible make a forcedownload.lua?