Add-ons for MSTS

How do I install add-ons for MSTS? I’m just asking because I want some CPR power. I already found some websites like Train-sim.com and cpr.ca which have downloads.

All the add-ons have an instruction file attached. Some are self installing and have a consist too, so there is nothing else to do. Others you will need to create a consist to drive the add-on or to put it in a train. There are many variations on the install procedure, so it is hard to be specific.

Thanks for telling me about the instructions. Should make things easier. But now I have a new problem. Every time I try to download files, it says that I need permission from an administrator to download in the right section.