Of course they can. It involves downloading and setting up an app. Many are computer illiterate, but are very familiar with 600-800 dollar smartphones. My employees configure aps all the time on their smartphones.

The reason they aren't doing this in droves right now is because they mainly use physical cash and barter locally. A good percentage of their transactions happen on the grey market where they have no use for bitcoin until:

1) They are educated that Bitcoin exists
2) More and better translations appear for bitcoin and the apps
3) More local exchanges and remittances appear
4) more local merchants accept bitcoin

This will take time to roll out, but is already happening as we speak.