Your stating that you "already know how to save them in the correct format"
begs the question, "In what format did you save them?" because Access can
import an Excel .xls file!  Can you get either file to import?  Do you mean
that you don't know how to import the files or that when you attempt to imort
them the procedure fails?

When and if you do get these two files into Access tables, when you select
New in the queries window, you will see a choice that says Find unmatched...
Use this and follow the wizard through.