How would I go about adding a capo to a cdlc that I downloaded that didn't have it originally but needs it?

You would use "Track>Pro guitar>Set capo" and then change the fretting as appropriate. There's a trick where you can use "Track>Pro guitar>Set tuning" and tune up by the number of frets that represents the capo position, allow EOF to transpose the notes in the track, then go back and set the tuning back to what it was (and not have it transpose the notes this second time). If any notes were played open or using a fret lower than the capo position you'll have to figure out how to change those manually, and EOF will have highlighted such notes if you let it tranpose notes during the first tuning change step.

I just can't seem to get it to work correctly. It's Bob Seger's Old Time Rock N Roll from here

Please be more specific about what is not working.

The tab is in the wrong key, it either needs a capo on the 2nd fret, or the tuning to be F#,B,E,A,C#,F#. Instead of E,A,B progression it needs to be F#,B,C# to match the original recording that the charter used.

You still haven't explained which of the steps I suggested didn't work. Applying a capo at fret 2 would cause fret 2 to become the new nut position so a low E string open note now plays F#.

When I add the capo and repack the song it still doesn't show up in the game. The tool kit never says anything about a capo either.

You first need to add the capo in EoF, as @@raynebc described (then save of course). I'm assuming you've already done this?

From there you need to make sure that the Toolkit is using the correct/updated .xml. You may have to remove the existing one from the toolkit and then browse for the updated one manually. Once added into the toolkit, it should say (capo 2nd fret) in the list of arrangements.

I've added it in EOF, saved and then checked the .xml file to make sure it was the correct one to put in the arrangement and still it's a no go. Toolkit still doesn't have anything about a capo in the arrangement.

I finally got it to work, I was just using the wrong curse words!! LOL!