Listed on Audigon is an inexpensive and simple solution, the Olive media server. It can be controlled by an Iphone or Ipad and, if his system also has a remote volume control, there you go. I think this Olive will rip his CDs--I know Olive had a service where you could ship your CDs to them and it would come back loaded with your music. I don't think they're the end-all to digital servers, but in your friend's case, simplicity rules. It also streams music which would be appealing.
https://app.audiogon.com/listings/da-converters-olive-media-products-one-olive-one-1tb-brand-new-and-unopened-2014-08-14-digital-94117-san-francisco-ca
https://app.audiogon.com/listings/da-converters-olive-media-products-one-olive-one-1tb-brand-new-and-unopened-2014-08-14-digital-94117-san-francisco-ca