Clio iii brake shoe replacement

Hi, i have a 2007 clio iii 1.5 dci68 and have been quoted £75 to replace the Pagid brake shoes (rear). The parts are currently £22 and am debating doing it myself. Is it worth it? Can anyone provide a guide/run-through on how to replace please? P.s the cylinders are fine so don't need replacing. Thanks