First, read a good book.

Realize that your husband’s grandfather would absolutely love to read this. Determine to send it to him as a happy surprise in the mail.
Look for anything that resembles a box in order to package it. When nothing can be found, make good use of the inconveniently thick plastic bags that Smiths uses for their grocery pickup.
Don’t you worry, you little piece of near useless plastic, you’re about get reused.

Wrap the book up like so WITH NOTHING BUT THE BOOK INSIDE:

Take a hot morning bike ride to the post office. Arrive sweaty and stinky at the front of the line, just as other customers are piling into the building.

Ask the mail clerk to for postage to mail a book. When he asks you if there’s anything else inside the package, confidently shout in his face “NO!”, then fork over the $4 shipping fee.
Finally, anxiously wait 2 – 3 days for your grandpa-in-law to text you that he received the book and was looking forward to an afternoon of reading.
Good books make the world go round!