I had my CDL since the early days when first implemented in PA in 1986
Was simple, get the study book from DOT, study any section of endorsements you may need or want (air brakes, hazmat, doubles, tankers and so on)
They set up test stations around the state, I went to a fire house near Allentown, you would pick up any test booklet as I mentioned and sat down for an hour or more and took each test
If you passed each test you got the endorsements on your new license, no pre trip test, no driving test
It was done this way to get all the working truck drivers licensed as easy as possible and not affect the industry by putting them out of work
Many of the truckers got cassettes to listen to while driving to study
I remember many of the older truckers at the testing site really complaining of this “new law”
And they didn’t require a medical card then either