step 2 says the firefox icon should be dragged to the dock. It never appeared after step 1
I can't continue the process without step 2
Can you please explain what actually you are trying to do?
Make sure that Firefox gets installed properly.
Open the Firefox disk image file and drag the Firefox program into the Applications folder on your hard drive. You shouldn't double-click the Firefox application to run it from the disk image, but instead drag it out of the DMG folder.