We know each other for many years, and we share a strong distrust in the Gov, so it was not hard.
To make it easier, I proposed a deal: he's accepting my coins, but I'll convert them into Euros according to the current rate if he decides to sell.
It was in January. After the recent doubling of the value of the coins, he's now a convinced hodler:)
The technical side: we're both using mobile wallets for it (he doesn't have a PC). No payment processors etc, just a direct Bitcoin transaction. As we trust each other, we don't wait for confirmations, and I use the lowest fee allowed by the wallet (currently about $1.5). Still a bit more expensive for me than paying with cash, but I don't care.
The dude is a 60yo with 6 classes of education.