The DLC has dissapered from the internet and the Origin store. The only thing thats out is a copy for xbox360, nothing for PC though.
Pinnacle Station was taken offline, probably because it's below the Mass Effect quality standard. The only way to get it for PC, is by buying the Trilogy Edition.
I don't work for EA.
It isn't my intention to revive dead threads, but this info can be useful for people who are still looking to install the DLCs if they got ME1 in Steam, for example.
Just follow the instructions of this link:
It should install both Pinacle and BDTS.