You need a cassette player with an audio out, a PC with a sound card with audio in and a program file Audacity to do the recording. The program is free, the player and the PC aren't, but maybe you already have them.
I know, I know - it's an old subject! But, it's something I haven't had to do for ages so I thought I'd ask what the current methods are, and what the current equipment is, that people are using these days.
This has become necessary because a friend has asked me if it's possible to transfer all her old music and recorded radio shows onto an mp3 player. Right now, she's still using an old Sony Walkman.