You can upload images directly from within Photo Mechanic. The PhotoDeck uploader is included with Photo Mechanic starting with version 4.6.6 BUT MUST BE UPGRADED (latest version is v1.7) if you have an older version (compatible with PM5 only).
Open Photo Mechanic and go to "Photo Mechanic / Preferences / Files / Location of user Uploader templates" to choose the folder where you store uploader templates on your computer. You can create a new folder if you wish, for example under your Library folder if you are on a Mac.
Unzip the PhotoDeck_latest.zip archive into that folder (or move the unzipped PhotoDeck folder if your browser automatically unzipped the downloaded file) and restart Photo Mechanic
Done! When you choose "Upload" in Photo Mechanic, the PhotoDeck option should now appear along with the latest version number.