One other piece of advice. Remember that the programming software is written using the "this is how I want my scanner's programming to look" design, not a "keep what I have and add/change/delete this to it" design. What that means is the software will delete all existing programming and write a new programming load using what is currently in the software. If you think you'll just add one new frequency to what's there and you only have that one frequency in the software, your scanner will only have that one frequency once you're done.
You can have many different files on your computer with programming from your scanner. It's very good to have several so you can revert any changes if they don't work out as you expect. It will also allow you to do some special programming if you travel and reload your "home" programming once you return, assuming you correctly saved the files.
My process goes kinda like this:
1) Read the scanner's current programming into the software.
2) Save this file onto your computer using a useful name that includes a timestamp. (You'll use the File/Save As menu option). For example, "StartingProgrammingWS1085-20160607191500" indicating this is my starting program for my WS1085, written out June 7, 2016 at 7:15 PM.
3) Make all changes you want. Delete unwanted entries, add new ones or change existing ones as desired.
4) Save this file onto your computer using a useful name that includes a timestamp. (You'll use the File/Save As menu option). For example, "AddedBobsWreckerWS1085-20160607192000" indicating this is my program after adding "Bob's Wrecker's information to my WS1085, written out June 7, 2016 at 7:20 PM.
5) Write the information to the scanner.
Repeat as necessary, changing the filenames and timestamps as appropriate. Note, the date is in YYYYMMDD format to help the names sort in a more meaningful manner. Having the year first helps keep the order better.